This document discusses psychrometry and air conditioning. It begins by defining dry air and atmospheric air, and the specific and relative humidity of air. It then discusses dew point temperature and how to calculate it. The document introduces the psychrometric chart as a tool to determine air properties and outlines several air conditioning processes like heating, cooling, humidification and dehumidification. Key concepts like wet bulb temperature, adiabatic saturation and human comfort are also summarized. Specific air conditioning applications such as evaporative cooling, mixing of air streams and cooling towers are briefly described.
To design any air-conditioning unit, estimation of heating or cooling load is very important. It helps us in design different devices most importantly the humidifier (in case of winter) or de-humidifier (in case of summer).
Refrigeration and Air Conditioning System ComponentsAjaypalsinh Barad
The ppt contains detailed study of all the components used in refrigeration and air conditioning system with neat sketches and description. It is well formed as per the syllabus of GTU
What is meant by “Airconditioning”?
Human Comfort
Why do we need A.C.?
Advantages and Disadvantage of A.C.
Ideal room temperature
some terminology-
Dry-bulb temperature
Wet-bulb temperature:
Dew point
Latent heat
Absolute humidity
Relative humidity
Specific humidity
Sensible heat
Evaporating Cooling
Condensation
Enthalpy
Entropy
7. Classification of air conditioners
8. Windows AC- advantages
Parts of the Window Air Conditioners
Working
The refrigeration system,
Air circulation system-room air cycle and
The hot air cycle.
Ventilation system,
Control system,
electrical protection system.
9.Split or Ductless AC-
Advantages, parts indoor and outdoor,
Types-
Wall mounted
Floor mounted/Tower AC
Ceiling mounted/Cassette AC
Multi Split ACs
10. Central Air Conditioning System
Advantages and disadvantages
11. Key differences between "Window", "Split" and a "cassette" air conditioners.
12. Cooling capacity
13. Energy Efficiency
14.Energy Consumption
15.Energy Efficiency Ratio
16.Energy Saving Methods
17.Some AC brands
Refrigeration and Air Conditioning
1.Refrigeration System
Two types of valves are used on machine air conditioning systems:
Internally-equalized valve - most common
Externally-equalized valve special control
Internally-Equalized Expansion Valve
The refrigerant enters the inlet and screen as a high-pressure liquid. The refrigerant flow is restricted by a metered orifice through which it must pass.
As the refrigerant passes through this orifice, it changes from a high-pressure liquid to a low-pressure liquid (or passes from the
high side to the low side of the system).
Let's review briefly what happens to the refrigerant as we change its pressure.
As a high-pressure liquid, the boiling point of the refrigerant has been raised in direct proportion to its pressure. This has concentrated its heat content into a small area, raising the temperature of the refrigerant higher than that of the air passing over the condenser. This heat will then transfer from the warmer refrigerant to the cooler air, which condenses the refrigerant to a liquid.
The heat transferred into the air is called latent heat of condensation. Four pounds (1.8 kg) of refrigerant flowing per minute through the orifice will result in 12,000 Btu (12.7 MJ) per hour transferred, which is designated a one-ton unit. Six pounds (2.7 kg) of flow per minute will result in 18,000 Btu (19.0 MJ) per hour, or a one and one-half ton unit.
Valve details
The refrigerant flow through the metered orifice is extremely important, anything restricting the flow will affect the entire system.
If the area cooled by the evaporator suddenly gets colder, the heat transfer requirements change. If the expansion valve continued to feed the same amount of refrigerant to the evaporator, the fins and coils would get colder until they eventually freeze over with ice and the air flow is stopped.
A thermal bulb has a small line filled with C02 is attached to the evaporator tailpipe. If the temperature on the tail pipe raises, the gas will expand and cause pressure against the diaphragm. This expansion will then move the seat away from the orifice,
To design any air-conditioning unit, estimation of heating or cooling load is very important. It helps us in design different devices most importantly the humidifier (in case of winter) or de-humidifier (in case of summer).
Refrigeration and Air Conditioning System ComponentsAjaypalsinh Barad
The ppt contains detailed study of all the components used in refrigeration and air conditioning system with neat sketches and description. It is well formed as per the syllabus of GTU
What is meant by “Airconditioning”?
Human Comfort
Why do we need A.C.?
Advantages and Disadvantage of A.C.
Ideal room temperature
some terminology-
Dry-bulb temperature
Wet-bulb temperature:
Dew point
Latent heat
Absolute humidity
Relative humidity
Specific humidity
Sensible heat
Evaporating Cooling
Condensation
Enthalpy
Entropy
7. Classification of air conditioners
8. Windows AC- advantages
Parts of the Window Air Conditioners
Working
The refrigeration system,
Air circulation system-room air cycle and
The hot air cycle.
Ventilation system,
Control system,
electrical protection system.
9.Split or Ductless AC-
Advantages, parts indoor and outdoor,
Types-
Wall mounted
Floor mounted/Tower AC
Ceiling mounted/Cassette AC
Multi Split ACs
10. Central Air Conditioning System
Advantages and disadvantages
11. Key differences between "Window", "Split" and a "cassette" air conditioners.
12. Cooling capacity
13. Energy Efficiency
14.Energy Consumption
15.Energy Efficiency Ratio
16.Energy Saving Methods
17.Some AC brands
Refrigeration and Air Conditioning
1.Refrigeration System
Two types of valves are used on machine air conditioning systems:
Internally-equalized valve - most common
Externally-equalized valve special control
Internally-Equalized Expansion Valve
The refrigerant enters the inlet and screen as a high-pressure liquid. The refrigerant flow is restricted by a metered orifice through which it must pass.
As the refrigerant passes through this orifice, it changes from a high-pressure liquid to a low-pressure liquid (or passes from the
high side to the low side of the system).
Let's review briefly what happens to the refrigerant as we change its pressure.
As a high-pressure liquid, the boiling point of the refrigerant has been raised in direct proportion to its pressure. This has concentrated its heat content into a small area, raising the temperature of the refrigerant higher than that of the air passing over the condenser. This heat will then transfer from the warmer refrigerant to the cooler air, which condenses the refrigerant to a liquid.
The heat transferred into the air is called latent heat of condensation. Four pounds (1.8 kg) of refrigerant flowing per minute through the orifice will result in 12,000 Btu (12.7 MJ) per hour transferred, which is designated a one-ton unit. Six pounds (2.7 kg) of flow per minute will result in 18,000 Btu (19.0 MJ) per hour, or a one and one-half ton unit.
Valve details
The refrigerant flow through the metered orifice is extremely important, anything restricting the flow will affect the entire system.
If the area cooled by the evaporator suddenly gets colder, the heat transfer requirements change. If the expansion valve continued to feed the same amount of refrigerant to the evaporator, the fins and coils would get colder until they eventually freeze over with ice and the air flow is stopped.
A thermal bulb has a small line filled with C02 is attached to the evaporator tailpipe. If the temperature on the tail pipe raises, the gas will expand and cause pressure against the diaphragm. This expansion will then move the seat away from the orifice,
Basics of refrigeration engineering section bAkshit Kohli
i hope, it will helpful to the students and peoples in the search of topics mentioned
it is informative to study to even get passing marks or for revision
Humidifier
Terminology : psychometry , absolute humidity , relative humidity , dew point , wet bulb temperature , adiabatic saturation temperature
Dehumidifier
Psychometric chart and its uses
Measurement of humidity
Application of humidity control
Pschometry and psychometric properties.pptxbaghbana bajoi
what is Psychrometric?
Psychrometry is a branch of science in which we study the thermodynamics of air and moisture with primary objective of developing human comfort.
=> Saturated air. Saturated air is a saturated mixture of air and water vapor mixture, where the vapor is at the saturation temperature and pressure.
FOR EXAMPLE :
when we feel thirsty,we need water to quench the thirsty, similarly air also feel thirsty and it need water to quench it thirsty or air has affinity to absorb the water
When temperature is high, so causes the air feel more thirsty.
=> Saturated air;
Saturated air is that air which holds water vapour at its maximum concentration at a particular temperature and pressure.
subscribe my youtube channel and get information to click the link
https://youtube.com/channel/UCDnmS9L7EL3MqRkPl4MvXrg
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
Contact with Dawood Bhai Just call on +92322-6382012 and we'll help you. We'll solve all your problems within 12 to 24 hours and with 101% guarantee and with astrology systematic. If you want to take any personal or professional advice then also you can call us on +92322-6382012 , ONLINE LOVE PROBLEM & Other all types of Daily Life Problem's.Then CALL or WHATSAPP us on +92322-6382012 and Get all these problems solutions here by Amil Baba DAWOOD BANGALI
#vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore#blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #blackmagicforlove #blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #Amilbabainuk #amilbabainspain #amilbabaindubai #Amilbabainnorway #amilbabainkrachi #amilbabainlahore #amilbabaingujranwalan #amilbabainislamabad
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSEDuvanRamosGarzon1
AIRCRAFT GENERAL
The Single Aisle is the most advanced family aircraft in service today, with fly-by-wire flight controls.
The A318, A319, A320 and A321 are twin-engine subsonic medium range aircraft.
The family offers a choice of engines
Vaccine management system project report documentation..pdfKamal Acharya
The Division of Vaccine and Immunization is facing increasing difficulty monitoring vaccines and other commodities distribution once they have been distributed from the national stores. With the introduction of new vaccines, more challenges have been anticipated with this additions posing serious threat to the already over strained vaccine supply chain system in Kenya.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Courier management system project report.pdfKamal Acharya
It is now-a-days very important for the people to send or receive articles like imported furniture, electronic items, gifts, business goods and the like. People depend vastly on different transport systems which mostly use the manual way of receiving and delivering the articles. There is no way to track the articles till they are received and there is no way to let the customer know what happened in transit, once he booked some articles. In such a situation, we need a system which completely computerizes the cargo activities including time to time tracking of the articles sent. This need is fulfilled by Courier Management System software which is online software for the cargo management people that enables them to receive the goods from a source and send them to a required destination and track their status from time to time.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
2. 2
Objectives
• Differentiate between dry air and atmospheric air.
• Define and calculate the specific and relative
humidity of atmospheric air.
• Calculate the dew-point temperature of
atmospheric air.
• Relate the adiabatic saturation temperature and
wet-bulb temperatures of atmospheric air.
• Use the psychrometric chart as a tool to
determine the properties of atmospheric air.
• Apply the principles of the conservation of mass
and energy to various air-conditioning processes.
3. 3
DRY AND ATMOSPHERIC AIR
Atmospheric air: Air in the atmosphere containing
some water vapor (or moisture).
Dry air: Air that contains no water vapor.
Water vapor in the air plays a major role in human
comfort. Therefore, it is an important consideration
in air-conditioning applications.
The cp of air can be
assumed to be constant
at 1.005 kJ/kg·°C in the
temperature range −10
to 50°C with an error
under 0.2%.
Water vapor in air behaves as if it existed alone
and obeys the ideal-gas relation Pv = RT. Then the
atmospheric air can be treated as an ideal-gas
mixture:
Pa Partial pressure of dry air
Pv Partial pressure of vapor (vapor pressure)
4. 4
Below 50°C, the h = const. lines
coincide with the T = const. lines in the
superheated vapor region of water.
h = h(T ) since water
vapor is an ideal gas
For water
hg = 2500.9 kJ/kg at 0°C
cp,avg = 1.82 kJ/kg · °C at −10 to 50°C range
In the temperature range
−10 to 50°C, the hg of
water can be determined
from Eq. 14-4 with
negligible error.
5. 5
SPECIFIC AND RELATIVE HUMIDITY OF AIR
Absolute or specific humidity
(humidity ratio): The mass of water
vapor present in a unit mass of dry air.
For saturated air, the vapor
pressure is equal to the saturation
pressure of water.
Saturated air: The air saturated with
moisture.
Relative humidity: The ratio of the amount
of moisture the air holds (mv) to the
maximum amount of moisture the air can
hold at the same temperature (mg).
The difference between specific
and relative humidities.
6. 6
What is the relative humidity
of dry air and saturated air?
In most practical applications, the
amount of dry air in the air–
water-vapor mixture remains
constant, but the amount of water
vapor changes.
Therefore, the enthalpy of
atmospheric air is expressed per
unit mass of dry air.
The enthalpy of moist (atmospheric) air is
expressed per unit mass of dry air, not per
unit mass of moist air.
Dry-bulb temperature:
The ordinary
temperature of
atmospheric air.
7. 7
DEW-POINT
TEMPERATURE
Constant-presssure cooling of moist
air and the dew-point temperature on
the T-s diagram of water.
Dew-point temperature Tdp:
The temperature at which
condensation begins when the air
is cooled at constant pressure
(i.e., the saturation temperature of
water corresponding to the vapor
pressure.)
When the temperature of a
cold drink is below the dew-
point temperature of the
surrounding air, it “sweats.”
8. 8
ADIABATIC SATURATION
AND WET-BULB
TEMPERATURES
The adiabatic saturation
process and its representation
on a T-s diagram of water.
The specific humidity (and relative humidity) of
air can be determined from these equations by
measuring the pressure and temperature of air
at the inlet and the exit of an adiabatic saturator.
9. 9
A simple arrangement to
measure the wet-bulb
temperature.
The adiabatic saturation
process is not practical.
To determine the
absolute and relative
humidity of air, a more
practical approach is to
use a thermometer
whose bulb is covered
with a cotton wick
saturated with water and
to blow air over the
wick.
The temperature
measured is the wet-
bulb temperature Twb
and it is commonly used
in A-C applications.
For air–water vapor mixtures at atmospheric
pressure, Twb is approximately equal to the
adiabatic saturation temperature.
Sling psychrometer
10. 10
THE PSYCHROMETRIC CHART
Schematic for a psychrometric chart. For saturated air, the dry-bulb, wet-bulb,
and dew-point temperatures are identical.
Psychrometric charts: Present moist air properties in a convenient form. They are
used extensively in A-C applications. The psychrometric chart serves as a valuable
aid in visualizing the A-C processes such as heating, cooling, and humidification.
11. 11
HUMAN COMFORT
AND AIR-
CONDITIONING
We cannot
change the
weather, but we
can change the
climate in a
confined space
by air-
conditioning.
A body feels comfortable when
it can freely dissipate its waste
heat, and no more.
Today, modern air-conditioning systems can heat,
cool, humidify, dehumidify, clean, and even
deodorize the air–in other words, condition the air
to peoples’ desires.
The rate of heat generation by human body
depends on the level of the activity. For an average
adult male, it is about 87 W when sleeping, 115 W
when resting or doing office work, and 440 W when
doing heavy physical work.
When doing light work or walking slowly, about half
of the rejected body heat is dissipated through
perspiration as latent heat while the other half is
dissipated through convection and radiation as
sensible heat.
12. 12A comfortable environment.
The comfort of the human body
depends primarily on three factors: the
(dry-bulb) temperature, relative
humidity, and air motion.
The relative humidity affects the
amount of heat a body can dissipate
through evaporation. Most people
prefer a relative humidity of 40 to 60%.
Air motion removes the warm, moist air
that builds up around the body and
replaces it with fresh air. Air motion
should be strong enough to remove
heat and moisture from the vicinity of
the body, but gentle enough to be
unnoticed.
An important factor that affects human
comfort is heat transfer by radiation
between the body and the surrounding
surfaces such as walls and windows.
Other factors that affect comfort are air
cleanliness, odor, and noise.
In an environment at 10°C with 48
km/h winds feels as cold as an
environment at -7°C with 3 km/h
winds as a result of the body-
chilling effect of the air motion (the
wind-chill factor).
13. 13
AIR-CONDITIONING PROCESSES
Various air-conditioning processes.
Maintaining a living space or an
industrial facility at the desired
temperature and humidity requires
some processes called air-
conditioning processes.
These processes include simple
heating (raising the temperature),
simple cooling (lowering the
temperature), humidifying (adding
moisture), and dehumidifying
(removing moisture).
Sometimes two or more of these
processes are needed to bring the
air to a desired temperature and
humidity level.
Air is commonly heated and
humidified in winter and cooled and
dehumidified in summer.
14. 14
Most air-conditioning processes can be modeled as steady-flow
processes with the following general mass and energy balances:
The work term usually consists of the fan work input, which is
small relative to the other terms in the energy balance relation.
Energy balance
Mass balance
15. 15
Simple Heating and Cooling (ω = constant)
During simple heating, specific humidity remains
constant, but relative humidity decreases.
Many residential heating systems consist of a stove, a heat pump, or an electric
resistance heater. The air in these systems is heated by circulating it through a
duct that contains the tubing for the hot gases or the electric resistance wires.
Cooling can be accomplished by passing the air over some coils through which a
refrigerant or chilled water flows.
Heating and cooling appear as a horizontal line since no moisture is added to or
removed from the air.
Dry air mass balance
Water mass balance
Energy balance
During simple cooling, specific
humidity remains constant, but
relative humidity increases.
16. 16
Heating with Humidification
Problems with the low relative humidity resulting from simple heating can be
eliminated by humidifying the heated air. This is accomplished by passing the air
first through a heating section and then through a humidifying section.
18. 18
Cooling with Dehumidification
The specific humidity of air remains constant during a simple cooling process,
but its relative humidity increases. If the relative humidity reaches undesirably
high levels, it may be necessary to remove some moisture from the air, that is,
to dehumidify it. This requires cooling the air below its dew-point temperature.
19. 19
Evaporative Cooling
Water in a porous jug left in an open,
breezy area cools as a result of
evaporative cooling.
In desert (hot and dry) climates, we can
avoid the high cost of conventional
cooling by using evaporative coolers,
also known as swamp coolers.
As water evaporates, the latent heat of
vaporization is absorbed from the water
body and the surrounding air. As a
result, both the water and the air are
cooled during the process.
This process is essentially identical
to adiabatic saturation process.
20. 20
Adiabatic Mixing of Airstreams
When two airstreams at states 1 and 2
are mixed adiabatically, the state of the
mixture lies on the straight line
connecting the two states.
Many A-C applications require the mixing of
two airstreams. This is particularly true for
large buildings, most production and process
plants, and hospitals, which require that the
conditioned air be mixed with a certain fraction
of fresh outside air before it is routed into the
living space.
21. 21
Wet Cooling Towers
Power plants, large air-conditioning
systems, and some industries
generate large quantities of waste
heat that is often rejected to cooling
water from nearby lakes or rivers.
In some cases, however, the cooling
water supply is limited or thermal
pollution is a serious concern.
In such cases, the waste heat must
be rejected to the atmosphere, with
cooling water recirculating and
serving as a transport medium for
heat transfer between the source and
the sink (the atmosphere).
One way of achieving this is through
the use of wet cooling towers.
A wet cooling tower is essentially a
semi-enclosed evaporative cooler.
An induced-draft counterflow cooling tower.
22. 22
Two natural draft cooling towers on a
roadside. A spray pond.
Natural-draft cooling tower: It looks like a large chimney and works like an
ordinary chimney. The air in the tower has a high water-vapor content, and thus
it is lighter than the outside air. Consequently, the light air in the tower rises, and
the heavier outside air fills the vacant space, creating an airflow from the bottom
of the tower to the top.
Spray pond: The warm water is sprayed into the air and is cooled by the air as
it falls into the pond,
Cooling pond: Dumping the waste heat into a still pond, which is basically a
large artificial lake open to the atmosphere.