Good Reduction Performance Research Articles

DYNAMIC POWER CONSUMPTION IN BASE TRANSCEIVER STATION (BTS) IN MGBAKWU ANAMBRA STATE USING MULTI-ATTRIBUTE DECISION MAKING TECHNIQUE

This work focused on reducing the Dynamic Power Consumption in BTS and Cellular Networks in Mgbakwu, Anambra State Nigeria using a Multi-Attribute Decision Making Technique that can represent the probabilistic nature of Cellular Network and Traffic generation that is cost effective and also gives better performance in reduction of the frequent measurement of BTS. The weighted sum of the normalized Attributes is called the Utility function which the Technique chooses. Measurements conducted in the two BTS of interest confirmed that Mgbakwu BTS is situated in a Rural/Residential environment and has two Peak (Busy) Hour periods for morning 9.55Erlangs from 7.30am to 8.30am and in the evening, 10.68Erlangs from 8.30pm to 9.30pm.

Collaborative Reverse Logistics Network for Infectious Medical Waste Management during the COVID-19 Outbreak.

The development of COVID-19 in China has gradually become normalized; thus, the prevention and control of the pandemic has encountered new problems: the amount of infectious medical waste (IMW) has increased sharply; the location of outbreaks are highly unpredictable; and the pandemic occurs everywhere. Thus, it is vital to design an effective IMW reverse logistics network to cope with these problems. This paper firstly introduces mobile processing centers (MPCs) into an IMW reverse logistics network for resource-saving, quick response, and the sufficient capacity of processing centers. Then, a multi-participant-based (public central hospitals, disposal institutions, the logistics providers, and the government) collaborative location and a routing optimization model for IMW reverse logistics are built from an economic, environmental perspective. An augmented ε-constraint method is developed to solve this proposed model. Through a case study in Chongqing, it is found that for uncertain outbreak situations, fixed processing centers (FPCs) and MPCs can form better disposal strategies. MPC can expand the processing capacity flexibly in response to the sudden increase in IMW. The results demonstrate good performance in reduction in cost and infection risk, which could greatly support the decision making of IMW management for the government in the pandemic prevention and control.

Assessment of Sewage Sludge and Coir Pith as Alternative Cover Materials to Red Soil in Bioreactor Landfills

This study assessed the performance of sewage sludge and coir pith as a potential alternative to virgin red soil as cover material in bioreactor landfills. Three field scale models of anaerobic bioreactor landfills were set up so as to study the performance of the cover materials on leachate generation time, quality and quantity. In one reactor (R1), red soil was used as the cover and was kept as control. In the other two reactors (R2 and R3), modified sewage sludge and coir pith were used as the cover materials, respectively. The leachate produced from each were analyzed based on its quality (Total Solids, pH, BOD, COD, Nitrate and Iron), quantity and generation time. Red soil provided respectively 41.08% and 25.5% reduction in BOD than modified sewage sludge and coir pith. However, coir pith showed better performance in reduction of leachate quantity, total solids, nitrate and iron, thus making it suitable for use as an alternate cover material.

Sustainability Evaluation and Optimization on the Modern Agro-Pastoral Circular System Integrating Emergy Analysis and Life Cycle Assessment

Developing modern circular agriculture is one of the important ways to promote agricultural sustainable development, facilitating the achievement of the Sustainable Development Goals adopted by the United Nations. However, when agricultural production operators constructed particular systems, they often lacked accurate data support and parameter matching. Consequently, problems such as unknown input and output, low circulation efficiency, and lack of comprehensive evaluation occurred, increasing challenges for efficient circulation of the systems. Therefore, based on sufficient data collection and field investigation, this research integrated emergy analysis and life cycle assessment to conduct sustainability evaluation on the modern Straw–Sheep–Cropland agro-pastoral circular system. Then the system was optimized by means of coupling parameter adjustment and key technology regulation. The results showed that the whole system required lower total emergy input after optimization. And the total weighted value of potential environmental impacts of the optimized system was 47.12% of that of the original system. Meanwhile, annual environmental service emergy in air, water, and soil was reduced significantly compared with the original one. In general, the optimized system had good performance in reduction, reuse, and controllability, so its sustainability was also high. This research formed a systematic method suitable for evaluating and optimizing the modern agro-pastoral circular system, which provided accurate guidance for the scientific construction and sustainable development of circular agriculture systems.

A Green Method toward Graphene Oxide Reduction by Extracellular Polymeric Substances Assisted with NH4+

Extracellular polymeric substances (EPS) occur naturally and widely on the surface of microbial cells; their reducibility may play a crucial role in graphene oxide reduction. In this work, the conversion of graphene oxide (GO) into reduction graphene oxide (rGO) with EPS (extracted from Bacillus sp.NT 10) as green reductant had been conducted to explore their potential application for graphene preparation. The results showed the GO could be reduced by EPS, especially in the presence of NH4+, and a synergetic effect was found between EPS and NH4+. Further studies hinted the rGO could be also obtained from GO by EPS reduction even under a mild alkaline condition (pH = 8), lightly higher room temperature (40 °C) and a certain amount of time (24 h). The good reduction performance was found to be ascribed to the real deoxygenation of oxygenous functional groups and restoration of electronic conjugation within GO, according to the analysis of XRD, XPS and FT-IR as well as Raman spectra, while the electron-rich tryptophan-like protein and aromatic protein on the surface of EPS as well as the assistance of NH4+ should account for the deoxygenation and restoration in terms of the detection on Zeta potential, AFM and 3D-EEM. These findings revealed the reduction of GO with EPS would be a green, environment-friendly and promising path to obtain rGO, which may open a novel route for the preparing graphene alternatively.

Enhancing climate resilience of vertical seawall with retrofitting - A physical modelling study

Coastal defence structures are playing a vital role in protecting coastal communities from extreme climatic conditions and flooding. With climate change and sea-level rise in the next decades, the freeboard of existing coastal defences is likely to be reduced and the probability of wave overtopping for these coastal defences will increase. The wave overtopping from coastal defences increases the probability of coastal inundation and flooding, imposing threat to the communities which are living in low-lying coastal areas. Retrofitting of existing seawalls offers the potential to enhance coastal resilience by allowing them to adapt and respond to changing climatic conditions. This study investigates a range of possible physical configurations and optimum retrofit geometry to maximize the protection of existing seawalls from wave overtopping. A comprehensive physical modelling study of four retrofit prototypes, including recurve wall, model vegetation, reef breakwater and diffraction pillars, was conducted to examine their performance in mitigating wave overtopping, when placed in front of a vertical seawall. All the tests were conducted on 1:20 smooth beach slope. Each test case consisted of approximately 1000 pseudo-random waves based on the JONSWAP spectrum. The physical modelling experiments were designed to include both impulsive and non-impulsive wave conditions. This study provides new predictive relations and decision support tool needed to evaluate overtopping risks from existing seawalls with retrofits under various hydrodynamic conditions. The analysis of experimental measurements demonstrates that wave overtopping from retrofitting structures can be predicted with similar relations for vertical seawalls, and by using a reduction factor which varies with geometric shapes. Statistical measures and sensitivity analysis show that recurve walls have the best performance in reduction of wave overtopping volume followed by model vegetation and reef breakwater. The measurements show the insignificance of diffraction pillars, at least for the selected configurations investigated, in mitigating wave overtopping.

Performance Evaluation of Textured Inserts with MQL in Machining of PH Stainless Steel

This present investigation presents the method of texture fabrication and performance analysis of machinability of a textured and conventional Tungsten Carbide (WC) tool inserts. An endeavour has been taken to increase the performance of machining with different type of textured inserts. Texturing on the rake face of the inserts was fabricated using Wire Electrical Discharge Machine (WEDM). Experiments were conducted with different set of machining parameters on PH Stainless Steel (PHSS) with conventional and textured inserts and machinability analysis were evaluated. Tangential cutting force, surface roughness, and tool wear have been opted as the responses. Scanning electron microscope and optical microscopic image were used to evaluate the tool wear for different type of texture inserts. Based upon the outcomes attained, it is observed that the cutting tool with diamond shape texture exhibits the better performance in reduction of cutting force, tool wear and also improves the surface finish.

Effect of geometric parameters on the performance of motorcycle catalytic converters

The critical environmental issues of the Indonesian automotive market growth are the increase in air pollution. Vehicle exhaust emission can cause significant problems for the human health and the environment. Therefore, vehicle emission control is indispensable to mitigate the environmental problem. One of the most widely used methods to reduce automotive emission is utilization of catalytic converter in exhaust system. In fact, the catalyst performance in the reduction of noxious gases depends on its material and geometric design. This study aims to evaluate the effect of geometric parameter on the performance of motorcycle catalytic converters. In this experimental study, the catalytic converter made of brass foil plate is mounted on motorcycle muffler. The effectiveness of three catalyst geometry models namely flat perforated plate, folded perforated plate and rolled brass sheet, will be evaluated in relation to the reduction of hydrocarbon (HC) and carbon monoxide (CO) content. HC and CO emission levels are measured by four gas analyzers. The results show that the geometric parameter has a significant effect on HC and CO’s composition in the exhaust gas. For idle speed test, the second geometry model of catalyst presents the best performance in reduction of Hydrocarbon and CO2 concentration.

Optimal designing of static var compensator to improve voltage profile of power system using fuzzy logic control

The unbalanced and nonlinear characteristic of many loads connected to the power system can cause power quality problems, which in turn affects other consumers. Electric arc furnaces (EAF) are among the loads that cause major problems for system power quality. The use of static var compensator (SVC) is a way to reduce power quality problems caused by EAF. Since precise quantification of the SVC susceptance function can greatly influence the optimization of the reactive power, in this paper proposed using of a fuzzy logic controller to optimize the susceptance function to further improve the voltage profile and reduce SVC capacitance. The results from simulations show that the SVC based fuzzy method optimally determines the coefficient of the susceptance function. The results show that the proposed method with the proposed method has good performance in reduction of harmonic currents and improving the voltage profile of the system. So, the results clear that in case of EAF load, the SVC is capable of rapidly compensating its effect and improve the system power quality. By maintaining the bus voltage and eliminating voltage oscillations, the active power received is quickly stabilised and power oscillations are removed. Thus, power quality problems of EAF application is eliminated with application of optimized SVC based fuzzy method. In addition, the performance of the proposed method compared to mathematical methods in previous studies has been evaluated, which presents superiority of the proposed method in reducing voltage oscillations and reducing harmonic currents.

Reducing static roof displacement and axial forces of columns in tall buildings based on obtaining the best locations for multi-rigid belt truss outrigger systems

In this paper, energy method as a robust method has been used to compute the optimum locations of belt truss and outrigger systems. To achieve this aim, a tall building of constant stiffness along its height, reinforced with a framed tube, shear core and belt truss with outrigger systems has been considered. An equivalent cantilevered beam has been used to model the framed tube system. Here, outrigger–belt truss systems are modeled by rotational springs placed at their spatial position. Utilizing the energy method, belt truss systems are placed at particular positions along the structure’s height, selected so to maximize energy absorption and dissipation. Applicability and accuracy of the proposed method are verified via a numerical example (50-story concrete building) and the results are compared with Stafford Smith’s method. The proposed method demonstrated for several belt truss and outrigger systems a reduction in the values of the roof displacement and axial force in comparison with Stafford Smith’s method. The results show that the structure with two belt–outrigger systems has a better performance in reduction of roof displacement and axial forces (2.3% and 4% reduction, respectively) rather than the one- and three-belt truss systems.

Differentially improved soil microenvironment and seedling growth of Amorpha fruticosa by plastic, sand and straw mulching in a saline wasteland in northwest China

Amorpha fruticosa is often used to revegetate saline wasteland in the YinNan Irrigation Area, northwest China. However, the survival rate of transplanted A. fruticosa seedlings is constrained by its low tolerance to high soil salinity, drought, and low soil temperatures (Tsoil) at the early transplanting stage. This study aimed to evaluate the effects of three different mulches, including plastic mulch (PM), sand mulch (SM) and rice straw mulch (RSM), and control (CK) on the soil microenvironment and A. fruticosa seedling growth. The results indicated that PM (19.1–26.2 °C), followed by SM (18.6–26.1 °C), provided the highest Tsoil at 0–20 cm depth during the whole growing period, while RSM (16.5–21.5 °C) exhibited lower Tsoil than CK (15.8–22.0 °C) at all time except the later growing stage. RSM (7.1%–26.4%) retained soil water most effectively as compared to CK, followed by SM (3.2%–22.5%), and then PM (-0.6%–19.7%). PM (11.4%–18.5%) had the best performance in reduction of ECe at 0–80 cm depth, followed by RSM (10.5%–15.5%), and then SM (3.7%–7.4%). Still, PM exhibited the greatest improvement in soil structure. A. fruticosa seedlings grown in PM achieved the best stand establishment and growth characteristics, in which its root reached to 40–60 cm depth, while the counterparts in RSM showed the poorest performance in three mulching treatments. The results above suggest that PM is a promising strategy to promote the growth of transplanted halophytes in saline wasteland of the YinNan Irrigation Area and other areas with similar ecologies.

Combining nonthermal plasma with perovskite-like catalyst for NOx storage and reduction.

A new NOx storage and reduction (NSR) system is developed for NOx removal by combining perovskite-like catalyst with nonthermal plasma technology. In this hybrid system, catalyst is mainly used for oxidizing NO to NO2 and storing them, while nonthermal plasma is applied as a desorption-reduction step for converting NOx into N2. An innovative catalyst with a high NOx storage capacity and good reduction performance is developed by successive impregnation. The catalysts prepared with various metal oxides were investigated for NOx storage capacity (NSC) and NOx conversion. Characterization of the catalysts prepared reveals that addition of cobalt (Co) and potassium (K) considerably increases the performance for NSC. Results also show that SrKMn0.8Co0.2O4 supported on BaO/Al2O3 has good NSC (209μmol/gcatalyst) for the gas stream containing 500ppm NO and 5% O2 with N2 as carrier gas. For plasma reduction process, NOx conversion achieved with SrKMn0.8Co0.2O4/BaO/Al2O3 reaches 81% with the applied voltage of 12kV and frequency of 6kHz in the absence of reducing agents. The results indicate that performance of plasma reduction process (81%) is better than that of thermal reduction (64%). Additionally, mixed gases including 1% CO, 1% H2 and 1% CH4, and 2% H2O(g) are simultaneously introduced into the system to investigate the effect on NSR with plasma system and results indicate that performance of NSR with plasma can be enhanced. Overall, the hybrid system is promising to be applied for removing NOx from gas streams. Graphical abstract ᅟ.

Delayed adaptive output feedback sliding mode control for offshore platforms subject to nonlinear wave-induced force

In this paper the control problem for an offshore steel jacket platform subject to nonlinear wave-induced force is investigated by introducing several new types of adaptive sliding mode controllers. Three control schemes are presented to reduce the oscillation amplitudes of the offshore platform. The first scheme is named an adaptive output feedback integral sliding mode controller, which has a better performance in comparison with an integral sliding mode controller. By introducing an intentional time delay into the control channel, an adaptive output feedback integral sliding mode controller is proposed as the second scheme. This controller is called a delayed adaptive output feedback integral sliding mode controller. It shows a good performance in reduction of the internal oscillations and control force. In the third scheme, a combination of current states and delayed states is used in the sliding surface and control law. This control scheme is named a combinational delayed adaptive output feedback integral sliding mode controller. One advantage of this scheme is that it provides an appropriate response by increasing the time delay. According to the simulation results, the proposed control schemes can effectively improve the control performance of the offshore platform in comparison with several existing control schemes.

Performance analysis of a new ejector enhanced vapor injection heat pump cycle

This paper proposes a novel ejector enhanced vapor injection cycle (EVIC) for air-source heat pumps. In the EVIC system, an ejector associated with an additional flash tank is introduced to enhance the overall system performance at low ambient temperature. The performances of the EVIC using R22, R290 and R32 are evaluated using the developed mathematical model, and then compared with those of the basic vapor injection cycle (BVIC). According to the simulation results, the EVIC with R22, R290 and R32 have 2.6–3.1%, 3.2–3.7% and 2.9–3.1% improvement in coefficient of performance (COP), 6.0–8.4%, 7.3–10.2% and 6.7–8.2% improvement in volumetric heating capacity compared with those of the BVIC under the same given operating conditions. Simultaneously, the EVIC also shows a good performance in reduction of the compressor discharge temperature at the given operating conditions. The performance characteristics of the EVIC may show its promise in heat pump applications.

Organic Farming Practice for Quality Improvement of Tea and Its Anti Parkinsonism Effect on Health Defense

Tea is an important beverage consumed worldwide. It is a source of important secondary metabolites like catechins monoterpenoids, carotenoids etc. Catechins are responsible for the beneficial health effects of tea. Over the decades conventional tea cultivation practice using synthetic fertilizer and pesticides has jeopardize the soil health particularly due to micronutrient deficiency, instability in yield and reduced product quality. Such threat has led to emergence of organic farming practice for improvement of crop yield and product quality that finally has an impact on human health defence. Field experiments conducted using organic farming practice has shown improved soil health by improving availability of micronutrients which in terms improved crop yield and quality of tea. The content of secondary phenolics compounds like total phenolics, GCG, EGCC, ECG was higher in when tea grown organically. Antioxidant property of tea extract from different farming practice was studied by DPPH method resulting higher radical scavenging capacity than tea grown conventionally. From the pharmacological study the organic tea extract has shown better control of Parkinsonism in two different animal model experiments. Organic tea extract exhibited better performance in reduction of Superoxide dismutase and catalase activity in brain in Parkinson’s disease induced in test mice model than the tea extract obtained from conventional farming practice. The value of SOD and catalase activity in MPTP induced mice model given tea extract grown in control, conventional farming, vermicompost and vermicompost+vermiwash treatment are respectively 1.31 ± 0.16c, 1.8 ± 0.16d, 0.95 ± 0.14e, 0.79 ± 0.06; and 0.98 ± 0.07c, 1.10 ± 0.07d, 0.78 ± 0.07e, 0.69 ± 0.05a for Tv 25 variety. Similar result is obtained for Tv1 variety also.The present study generated information on soil, crop performance, yield and quality of tea related to health defense, which should be regarded as valuable information for a perennial crop like tea.

Analysis of Low Velocity Dense Phase Pneumatic Conveying System to Extend System Conveying Capability

This paper reports the current development of technologies to analyse the conveying performance of bypass low velocity dense phase pneumatic conveying system for transporting powder bulk materials and slug flow low velocity dense phase pneumatic conveying system for transporting granular sized bulk materials. It reveals that the bypass system can be operated at a lowered air velocity than conventional pipe line and slug flow system can be also controlled to operate at a lower velocity zone. Hence these technologies have the potential to extend the conveying capability of a pneumatic conveying system to a broader range of materials, also provide better performance in reduction in pipe wear and product degradation.

Semi-active Seismic Isolation System with Controllable Friction Dampers Using Piezoelectric Actuators

Semi-active seismic isolation systems using controllable friction dampers had been proposed to reduce response accelerations and displacements comparing with those of passive systems, although they had a problem that the dampers might fail to generate damping forces due to malfunctions in strong earthquakes. To solve the problem, a new type of controllable friction damper with a fail-safe mechanism was developed in this study. For the damper, piezoelectric actuators were used to make the mechanism simple. The actuators are compact, and can make quick responses and produce large forces. Simulations and excitation tests were carried out for the semi-active system using the friction dampers, showing good performance in reduction of response acceleration and displacement together with higher reliability comparing with systems using conventional friction dampers.

Semi-Active Seismic Isolation System with Controllable Friction Dampers Using Piezoelectric Actuators

Semi-active seismic isolation systems using controllable friction dampers had been proposed to reduce response accelerations and displacements comparing with those of passive systems, although they had a problem that the dampers might fail to generate damping forces due to malfunctions in strong earthquakes. To solve the problem, a new type of controllable friction damper with a fail-safe mechanism was developed in this study. For the damper, piezoelectric actuators were used to make the mechanism simple. The actuators are compact, and can make quick responses and produce large forces. Simulations and excitation tests were carried out for the semi-active system using the friction dampers, showing good performance in reduction of response acceleration and displacement together with higher reliability comparing with systems using conventional friction dampers.