An energy flow analysis in a paper-based industry

Industrial sector is the largest user of energy in India and many parts of the world. More than half of the total energy is used in industries to operate various energy-using machineries. Energy conservation is a cost-effective approach in any energy optimization program that can be implemented in industrial activities. Energy-intensive industries in developing economies offer significant energy-saving potential owing to the technology gap as well as lower operating efficiency. A detailed energy flow analysis was conducted in a paper carton manufacturing unit in India to quantify the energy-saving potential. The study revealed that the compressed air leakage is responsible for about 50% of the total energy loss. The specific electrical and thermal energy consumption was estimated and found to be 91.85?kWh/ton and 1,619?MJ/ton of biomass, respectively. Annual energy saving potential was found to be 5.9% of the total annual energy consumption. The cost of DG power is found to be 389% higher than the grid power. The share of self-generated DG power is estimated to be 41% of the total power consumed. Electrical energy intensity of the plant could be reduced by 6.36% implementing energy conservation measures proposed in this study.     

Effect of Heat-Generating Solid Body on Mixed Convection Flow in a Ventilated Cavity

The mixed convection flow and heat transfer characteristics inside a square ventilated cavity with a heat-generating solid circular body located at the center have been investigated numerically. The inlet opening is at the bottom of the left wall, while the outlet one is at the top of the right wall, and all the walls of the cavity are considered to be adiabatic. A Galerkin weighted residual finite element method is used to solve the governing equations of mass, momentum, and energy. The behavior of the fluid in the ranges of dimensionless cylinder diameter from 0.1 to 0.6 of the heat generating body, thermal conductivity ratio range from 0.2 to 50 between solid and fluid, and heat generating parameter range from 1 to 5 is described in detail. The medium considered is air with a Prandtl number of 0.71. It is found that the flow and temperature field is strongly dependent on the already-mentioned parameters for the ranges considered. The variation of the mean Nusselt number, the dimensionless average drag force, and the average temperature of the fluid versus Richardson number are presented for these parameters.     

Development of a framework for sustainable improvement in performance of coal mining operations

Clean Technologies and Environmental Policy - India is a developing country, where boosting of modern energy supply is the primary requirement for economic growth. About two-thirds of this energy...     

Melatonin Modulates Plant Tolerance to Heavy Metal Stress: Morphological Responses to Molecular Mechanisms

Heavy metal toxicity is one of the most devastating abiotic stresses. Heavy metals cause serious damage to plant growth and productivity, which is a major problem for sustainable agriculture. It adversely affects plant molecular physiology and biochemistry by generating osmotic stress, ionic imbalance, oxidative stress, membrane disorganization, cellular toxicity, and metabolic homeostasis. To improve and stimulate plant tolerance to heavy metal stress, the application of biostimulants can be an effective approach without threatening the ecosystem. Melatonin (N-acetyl-5-methoxytryptamine), a biostimulator, plant growth regulator, and antioxidant, promotes plant tolerance to heavy metal stress by improving redox and nutrient homeostasis, osmotic balance, and primary and secondary metabolism. It is important to perceive the complete and detailed regulatory mechanisms of exogenous and endogenous melatonin-mediated heavy metal-toxicity mitigation in plants to identify potential research gaps that should be addressed in the future. This review provides a novel insight to understand the multifunctional role of melatonin in reducing heavy metal stress and the underlying molecular mechanisms.     

An end-use energy analysis in a Malaysian public hospital

The commercial sector consumes 8–50% of the total energy consumption for a few selected countries around the world. An energy audit was conducted in a Malaysian public hospital to identify energy using equipment and their energy consumption breakdown. Different energy saving measures have been identified and applied for electrical motors used in this hospital. It was estimated that this hospital consumed about 19,311 MW h for the year 2008. It was also estimated that about 212 MW h, 250 MW h and 317 MW h of annual energy can be saved using energy-efficient motors at 50%, 75% and 100% loads, respectively. In addition, use of variable speed drives are expected to save 1735 MW h, 4048 MW h and 6361 MW h of annual energy consumption for 20%, 40% and 60% speed reductions, respectively. It was found that the payback period for using high efficiency motors at different loads is less than a year which is economically very viable. However, the use of variable speed drives was found to be economically viable for larger motors for higher speed reductions. The study also found that a sizeable amount of emissions can be reduced for the different energy savings measures applied for electrical motors.     

Energy savings and emissions reductions for rewinding and replacement of industrial motor

Electric motors consume 30-80% of total industrial energy around the world. This study estimates the economic viability of replacing rewound and standard motors with high efficiency motors (HEMs) in the industrial sector. The efficiency of a motor is degraded when it is rewound and it is better to rewind a larger motor compared with a smaller motor. It was found that a HEM can save on average 5.5% of energy compared with a standard motor. In addition, the payback period was found to be reasonable when a motor is operated at a 50% load. HEMs will also save a sizeable amount of energy and reduce emissions. It was estimated that 67,868 MWh/year energy and US$ 4,343,531 per year could be saved by introducing HEMs. By contrast, 44,582 tons of CO₂, 333 tons of SO₂ and 122 tons of NO_x emissions could be reduced through the aforementioned energy savings. This study found that rewound motors of a larger size and HEMs are economically viable.     

Acute Myelogenous Leukemia Cells Secrete Factors that Stimulate Cellular LDL Uptake via Autocrine and Paracrine Mechanisms

Leukemic cells isolated from most patients with acute myelogenous leukemia (AML) have higher low density lipoprotein (LDL) uptake than normal mononuclear blood cells. Little is known, however, about the mechanism behind the elevated LDL uptake. We investigated if AML cells secrete factors that stimulate cellular LDL uptake. Mononuclear blood cells were isolated from peripheral blood from 42 patients with AML at diagnosis. Cellular LDL uptake was determined from the degradation rate of ¹²⁵I-labelled LDL. Conditioned media from AML cells stimulated the LDL degradation in the leukemic cell lines KG1 and HL60, and in isolated AML cells. The stimulatory effect correlated with the LDL degradation in the AML cells directly after isolation from blood. Conditioned media also autostimulated LDL degradation in the AML cells themselves. Concentrations of IL-6 and IL-8 in AML cell conditioned media correlated with the LDL degradation in AML cells directly after isolation from blood. Addition of R-TNF-α, but not IL-6 or IL-8, stimulated LDL degradation in HL60, KG1, and AML cells. The LDL degradation in AML cells could be inhibited by a LDL receptor blocking antibody. AML cells secrete factors that stimulate LDL uptake in a paracrine and autocrine pattern which open up therapeutic possibilities to inhibit the uptake of LDL by administration of antibodies to these factors.     

Energy, economic, and environmental analysis of the Malaysian industrial compressed-air systems

Compressed-air systems account for about 10% of the total industrial-energy use in Malaysia and some other countries. Compressed air is typically one of the most expensive utilities in an industrial facility. Opportunities for potential savings can thus be sought and identified. This article estimates the energy used by compressed-air systems in Malaysian industries. Various energy-saving measures, such as use of high efficient motors, variable speed drive (VSD), leak prevention, use of outside intake air, reducing pressure drop, recovering waste heat, and use of efficient nozzle, were applied to save compressed-air energy and then the results were compared with available literatures. For an electric motor used in a compressed air system, a sizeable amount of electric energy and utility bill have been found to be saveable using high efficient motors and applying VSDs in matching the speed requirements. Also, significant amounts of energy and emission are reducible through various energy-saving strategies. Payback periods for different energy saving measures have been estimated and found to be economically viable in most cases.     

Effects of operating variables on heat transfer and energy consumption of a household refrigerator-freezer during closed door operation

Refrigerator-freezers play an important role in the preservation of perishable food in warm and humid climates. Experiments were conducted in a controlled chamber to investigate the effects of the ambient temperature, cabinet load, thermostat setting and an open surface water pan on the heat transfer and energy consumption of refrigerators. The operating variables have strongly influence the heat transfer and energy consumption.