An air conditioning system providing cooling, water heating and drying

In the tropics, air conditioning is essential as the operating daily ambient temperature is high. In Malaysia and Singapore, most of the houses and apartments are air conditioned, at least one room. Every kW of electricity consumed by the air conditioner, about 4 kW is thrown into the atmosphere. Energy is available at the inlet to the condenser at about 85oC and can be utilized for useful purposes. Here, waste heat from air conditioners is utilized for water heating and drying purposes. A water condenser fitted at the exit of compressor absorbs most of the superheat and latent heat. Even a 60% recovery of this waste energy can heat 200 litres of water to 60oC within about three hours. A dryer connected at the exit of air condenser is fitted with filter to supply clean hot air to the dryer. The system reduces global warming and the payback period is less than two years

Power generation from waste of IC engines

Several methods for waste thermal energy recovery from internal combustion engine (ICE) have been studied by using supercharger or turbocharger and /or combined. This study presents an innovative approach on power generation from waste of IC engine based on coolant and exhaust. The waste energy harvesting system of coolant (weHSc) is used to supply hot air at temperatures in the range of 60–70 C directly into the engine cylinder, which would be useful to vaporize the fuel into the cylinder. The waste energy harvesting system of exhaust system (weHSex) has been developed with integrating fuzzy intelligent controlled Micro-Faucet emission gas recirculation (MiF-EGR) and thermoelectric generator (TEG). In this study the MiF-EGR (micro-facet exhaust gas recirculation) will be used to maintain the intake temperature 70 C by keeping flow of the exhaust to the engine cylinder chamber and to increase the engine volumetric efficiency. The TEG produces electrical power from heat flow across a temperature gradient of exhaust and delivers DC electrical power to the vehicle electrical system which could reduce the load of the alternator by as much as 10%. The performance of weHS equipped engine has been investigated by using GT suite software for optimum engine speed of 4000 rpm. The result shows that specific fuel consumption of engine has improved by 3% due to reduction of HC formation into the engine combustion chamber causes significantly improved the emission. While, the brake power has been increased by 7% due to the fuel atomization and vaporization at engine intake temperature 70 C

Performance of evaporator collector and air collector in a solar assisted heat pump dryer

A solar assisted heat pump dryer has been designed, fabricated and tested. This paper presents the performance of evaporator-collector and air collector, when operated under same meteorological conditions. ASHRAE standard procedure of collector testing has been followed. The absorber platce of the evaporator-collector is made of copper plate painted black without any glazing. At the bottom of the absorber plate, a tube has been soldered in serpentine form. Areas of the evaporator-collector and air collector are 1.5 m2 and 1.24 m2, respectively. The evaporator-collector of the heat pump is acting directly as the solar collector and the temperature of refrigerant at the inlet to the evaporator-collector always remained below the ambient temperature. Due to rejection of sensible and latent heat of air at the dehumidifier. the temperature at the inlet to the air collector is lower than the ambient air. Hence, the thermal efficieney of the air collector also increases due to a reduction of losses from the collector. The efficiency of evaporator-collector and air collector varied between 0.8 - 0.86 and 0.7 - 0.75, respectively

NANO-BATTERY TECHNOLOGY FOR EV-HEV PANEL: A PIONEERING STUDY

Global trends toward CO2 reduction and resource efficiency have significantly increased the importance of lightweight materials for automobile original equipment manufacturers (OEM). CO2 reduction is a fundamental driver for a more lightweight automobile. The introduction of Electrical Vehicles (EVs) is one initiative towards this end. However EVs are currently facing several weaknesses: limited driving range, battery pack heaviness, lack of safety and thermal control, high cost, and overall limited efficiency. This study presents a panel-style nano-battery technology built into an EV with CuO filler solid polymer electrolyte (SPE) sandwiched by carbon fiber (CF) and lithium (Li) plate. In addition to this, an aluminum laminated polypropylene film is used as the electromagnetic compatibility (EMC) shield. The proposed battery body panel of the EV would reduce the car weight by about 20%, with a charge and discharge capacity of 1.5 kWh (10% of car total power requirement), and provide the heat insulation for the car which would save about 10% power consumption of the air conditioning system. Therefore, the EV would be benefited by 30% in terms of energy reduction by using the proposed body. Furthermore, the proposed body is considered environmental-friendly since it is recyclable for use in a new product. However, the main limiting factors of the SPE are its thermal behavior and moderate ionic conductivity at low temperatures. The SPE temperature is maintained by controlling the battery panel charging/discharge rate. It is expected that the proposed panel-style nano-battery use in an EV would save up to 6.00 kWh in battery energy, equivalent to 2.81 liters of petrol and prevent 3.081 kg of CO2 emission for a travel distance of 100 km.   KEYWORDS: epoxy resin; carbon fiber; lithium thin plate; energy generation; solid electrolyte batter

WASTE HEAT RECOVERY IN HEAT PUMP SYSTEMS: SOLUTION TO REDUCE GLOBAL WARMING

Energy conversion technologies, where waste heat recovery systems are included, have received significant attention in recent years due to reasons that include depletion of fossil fuel, increasing oil prices, changes in climatic conditions, and global warming. For low temperature applications, there are many sources of thermal waste heat, and several recovery systems and potential useful applications have been proposed by researchers [1-4]. In addition, many types of equipment are used to recover waste thermal energy from different systems at low, medium, and high temperature applications, such as heat exchangers, waste heat recovery boiler, thermo-electric generators, and recuperators. In this paper, the focus is on waste heat recovery from air conditioners, and an efficient application of these energy resources. Integration of solar energy with heat pump technologies and major factors that affect the feasibility of heat recovery systems have been studied and reviewed as well.   KEYWORDS: waste heat recovery; heat pump

Prevalence of multidrug resistance bacterial isolates from infected wound patients in Dhaka, Bangladesh: A cross-sectional study

Abstract Introduction Multidrug resistance (MDR) is threatening the adequate coverage of antibiotics. This study aimed to analyze the antimicrobial resistance pattern of bacterial isolates from wound infection and the scenario of multidrug resistance. Methods Microbiological culture results scripts of Medinova Medical Services LTD, representing non-repetitive various wound samples (post-surgical, trauma, superficial skin, burn) reported between January 2017 and March 2018, were retrieved and analyzed for pathogens and their antimicrobial resistance patterns using R version 3.5.3. Results Overall, 1266 bacterial isolates were obtained, and 850 (67.1%) were identified as MDR. The percentage of MDR among gram-positive and gram-negative bacterial isolates were 68.8% and 66.0%, respectively. Among isolates Staphylococcus aureus (n = 401), Pseudomonas aeruginosa (n = 200), and Escherichia coli (n = 193) were predominant. Vancomycin followed linezolid showed most activity against gram-positive bacteria. Whereas, Colistin was found to be the most active against most of the gram-negative bacterium except for the Proteus spp in sensitivity test. Although, carbapenem group was determined to be the best against Proteus spp. About 82% Enterococcus spp and 76% Proteus spp were MDR. Isolates from patients aged >60 years (AOR = 1.774 95%CI: 1.089–2.892) were more prone to becoming MDR in compared to other age group and was a significant determinant (P = 0.02) of MDR. Conclusions Our study revealed that the presence of MDR pathogens in wound infection was noteworthy. The findings of this study would assist in decision making of wound infection treatment

Workplace Violence Among Health Care Professionals in Public and Private Health Facilities in Bangladesh

Objectives: The main objectives of this study were to examine the prevalence of workplace violence (WPV), its associated factors and explore the experiences of healthcare workers. Methods: A hospital-based cross-sectional study design used a nationally representative sample of 1,081 healthcare workers covering eight administrative divisions of Bangladesh. Logistic regression analysis was employed to estimate the adjusted effect of independent factors on WPV among healthcare workers. Results: Of the participants, 43% (468) experienced some form of WPV. Of those, 84% reported experiencing nonphysical violence, and 16% experienced physical violence in the past year. About 65% of victims claimed no action was taken to investigate the incident, and 44% reported no consequence for perpetrators. Four factors: being married (AOR = 1.63; CI: 1.12–2.39); public sector healthcare worker (AOR = 2.74; CI:1.99–3.76); working in an emergency department (AOR = 2.30; CI:1.03–5.12); and undertaking shift work (AOR = 1.52; CI: 1.10–2.11) were found to be significantly associated with WPV. One-third of the participants were worried about violence in their workplace. Conclusion: WPV is highly prevalent among healthcare workers in Bangladesh. Formal guidelines for reporting and managing WPV are urgently needed at the individual, hospital, and national levels