This study aims to determine the self-purification of Lake Maninjau based on the depth stratification. Sampling was carried out at the locations where there was lake water use, namely in the middle, domestically, in the hydropower area, in the endemic fisheries and at the aquaculture cages under SNI 6989.57: 2008. The measured parameters were BOD and the environmental parameters of pH, DO, and temperature were used to determine the lake stratification. Lake Maninjau's self-purification was determined by comparing the deoxygenation (K1) and reaeration (K2) coefficients. Based on the pH, DO, and temperature profiles, the epilimnion layer was found at 0-22 m depth and the hypolimnion layer started at a depth of 22 m. The BOD concentrations obtained did not meet the Government Regulation quality standards of 21.87-47 mg/L. The deoxygenation coefficient K1 in the epilimnion layer ranged from 0.04-1.49/day while in the hypolimnion layer it ranged from 0.08-0.54/day. The reaeration coefficient K2 in the epilimnion layer ranged from 0.04 to 0.57/day while in the hypolimnion layer, it ranged from 0.005 to 0.04/day. Wind speed and depth play a significant role in determining the lake’s self-purification capacity. The self-purification of the lake was still held mainly in the epilimnion layer at depths of 0-9 m while in the hypolimnion layer deeper than 22 m, its ability begins to diminish. This indicates that most of the lake waters have a significantly decreased natural self-purification capacity.

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In this work, we prepared Fe2O3 thin films using a pulsed laser deposition method. The Nd:YAG laser is used to prepare Fe2O3 films on a glass substrate under a temperature of 200°C, and the effects of laser energy on the structure and optical properties of thin films have also been studied. The optical properties of the absorption and transmission spectra of the formed thin films were studied. The direct bandgaps of the samples were obtained by measuring the absorption and transmittance spectrometers ranging from 2.3 to 2.7 eV. Using atomic force microscopy (AFM) technique and taking pictures, the surface structure of the formed films was studied. The size of the nanoparticle grains is observed in the range of (73.87), (69.28) and (102.38) nm for energy (700, 800, 900)mJ, respectively.

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The behavior of compression resistance perpendicular to the fiber of guadua bamboo test pieces was evaluated through an analysis of multifactorial variance (ANOVA). The samples object of studies came from four areas located in the municipality of Pitalito to the south of Huila department. They were tested at the Institute of Extension and Research (IEI) of the National University of Colombia in Bogotá. The 112 samples tested with compression perpendicular to the fiber obtained an average moisture content in the samples of the SA Group of 98.86% and in the samples of the SB Group of 113.51%, with standard deviations of 14.98% and 27.21% respectively. The analysis of multifactorial variance of Guadua angustifolia in relation to 3 factors (Area, Guadua Section, Saturation) through an experimental design, allowed to identify that the 3 factors and their interactions of first and second order do not have significant effects on the resistance to perpendicular compression with a p-value higher than 0.05. The admissible effort to perpendicular compression was also found according to the procedure described in the Colombian Seismic-Resistant Standard (NSR-10), finding that for the SA Group's test pieces, this effort is of greater magnitude than the one described in the standard. Finally, the Circumferential Elasticity Moduli were found according to the procedure described by L.A. Torres & García, (2007).

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The rapid prototyping by manufacturing of molten deposition (FDM) in 3D printer, has evolved rapidly in terms of printed materials such as polymers, metals and composites. Through this project we have designed a clay extrusion system (ceramic) that allows us to print objects in three dimensions quickly, either as a prototype, artistic products, among others. A literature search was made about types of clay extruders and their main components, the clay extrusion system was designed according to the printing variables (clay plasticity, exit velocity, mass flow and others), according to the design was followed by calculations and selection of materials for the extruder equipment. For the process of dragging the clay to the outlet nozzle, a screw or worm was selected in stainless steel, which was carried out stress analysis using the finite element software ANSYS® WORKBENCH. The output of the clay extruder is coupled through a hose to the extruder of the 3D printer, where the output speed of the material is regulated according to the type of product, drying, room temperature, relative humidity among others.

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Increasing productivity by applying hard and dry machining concepts is background of study. The concepts have been well implemented by using CBN and ceramic. However, high cost of CBN and ceramic makes metal cutting industry seeking other possible solutions. The alternative solution offered is carbide due to the development of coating materials and coating deposition technologies. In this research, the use of multilayer CVD-coated carbide (TiN/Al2O3/TiCN) when machining hardened steel AISI 1045 (40-45) HRc is studied. Focus of study is on formulating cutting condition and productivity, which represented by metal removal rate (MRR) and volume of material removal (VMR). Turning experiment was carried out by utilizing design of experiment factorial 23 with 4 center points. Wear mode including its evolution, machining time and surface roughness (Ra) were recorded. From the results of study, flank wear was observed as the wear mode of multilayer CVD-coated carbide. Cutting condition that could be resulted by the tool was v (250-350) m/min, f (0.14-0.24) mm/rev, a (1.5-2.5) mm with tool life at VB (0.22-0.24) mm was (2.2-19.5) minutes. Under the cutting condition, MRR (53-210) cm3/min and VMR (462-1059) cm3 were resulted and surface roughness was obtained at medium finish quality or grade N7. Case study was carried out in the related industry and result show that the productivity of sample product made of hardened steel AISI 1045 was successfully increased about (220-420)%. Those 8 cutting edges of multilayer CVD-coated carbide insert give great contribution to increase productivity.

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Washing has now become very crucial to human survival today having become part and parcel of our daily activities due to the outbreak of corona virus infectious disease 2019 (COVID-19) pandemic in the world. In Nigeria, efforts are geared towards developing indigenous/home based technologies for processing Nigerian agricultural produce into value-added, easy-to-transport and storable products due to food insecurity occasioned by the ravaging effects of COVID-19, alarming postharvest food losses, climate change and population upsurge. Nigeria is believed to have the capacity to feed the world, if appropriate technologies could be developed and deployed to her agriculture and postharvest handling/processing of farm produce. Thus a review of past researchers’ works on washing of farm produce is needful, being a very significant unit operation in food processing. To this effect, research papers and relevant materials were sought, obtained and reviewed from search engines and scientific databases. Hereby presented are a review of published researchers’ works; and research gaps on mechanized washing of agricultural produce across the globe, with a view to provide useful/helpful information to Nigerian indigenous technology developers and food processing industries as Nigeria strives to make it a policy to grow what she eats and eat what she grows. A machine, capable of washing leafy and non-leafy farm produce in the production line of a food processing plant, is also proposed/suggested. Through the information contained in it, this research is expected to serve as an impetus for researchers in this study area.

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University students spend most of their time in a sitting position. Prolonged sitting on ill-fitted furniture and the resulting lousy posture make students have different musculoskeletal disorders (MSDs) and are strictly related to students’ learning outcomes. This study aims to improve postural comfort of chairs placed inside the Science & Technology Library at the University of Salerno. A previous study about these library chairs showed that the lumbar area was the most suffering part while perceived (dis)comfort was dependent on time. Based on this, an ergonomic redesign and, consequently, manufacturing of the chair has been done. A perceived-comfort comparison between the library chair and the redesigned one has been performed. A statistical sample of 28 healthy students performed a 20-minutes experiment two times, alternatively on the library chair and the redesigned one. The 20-minutes experiment was divided into two 10-minutes tasks (“Reading & Writing” and “Laptop use”) to simulate a study day. The participants' postures were acquired non-invasively using cameras and processed by Kinovea; questionnaires were used to rate the perceived subjective (dis)comfort. A procedure for improving an existing product through a comfort-driven redesign is proposed. Results showed the redesigned library chair lead on increasing postural comfort (particularly in the lumbar area) thanks to the new design and modifications.

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Multi-carrier code-division multiple access system support multiple users at the same time over same frequency band. It is a multiple access scheme used in OFDM-based telecommunication systems. Though it is a promising wireless communication technology with high spectral efficiency and system performance, it is prone to multiple access interference (MAI). So, this paper mainly aims to design a MC–CDMA receiver to mitigate MAI. The classical receivers like maximal ratio combining (MRC), equal gain combining (EGC), and minimum mean square error (MMSE) fails to cancel MAI when the MC– CDMA is subjected to non-linearistic degradations. In this case, the neural network (NN) receivers could be a better alternative. The efficiency and effectiveness of the proposed ELM (Extreme Learning Machine) Algorithm based receiver is studied thoroughly and explained in detailed for the MC–CDMA with non-linearistic degradations.

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In this work, two controllers, a Proportional Integral (PI) and a Model-based Predictive Controller (MPC), have been designed to regulate a DC/DC Single-Ended Primary Inductance Converter (SEPIC). First, the modeling and linearization of the system was performed using a frequency response estimation method. Then, the PI controller was designed around a certain setpoint. Next, an algorithm was designed according to the Extended Prediction Self-Adaptive Control (EPSAC). Finally, the performance of the controllers was evaluated for setpoint tracking and disturbance rejection.

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The physical, chemical and microbiological parameters of the water in the El Salado stream were determined, taking into account nine parameters: turbidity, dissolved oxygen, BOD5, pH, nitrates, phosphates, fecal coliforms, total solids and temperature in order to compare with the regulations, after which the Water Quality Index of the National Sanitation Foundation (ICA - NSF) of the United States was calculated; For this, four monitoring campaigns were carried out between the months of February, March, April and May 2019; at four sampling points. The results obtained show that the water quality is within the range of Bad to Medium.

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The article devotes to the problem of controlling discrete nonlinear dynamical systems under non-parametric uncertainty. This term refers to the situation when the model structure of the object under study remains unknown to the parameters. Non-parametric models are considered, in which the difference equation degree of a dynamic process model is refined based on the rule of selection of significant variables. According to this rule, only those variables are included in the non-parametric model, whose optimal coefficient of kernel function is minimal. Non-parametric dual control algorithms are given. Control devices based on these algorithms perform not only the function of controlling the object itself, but also its study. The learning process of the dual control system with active accumulation of information is analyzed. The results of the computational experiment using the non-parametric adaptive dual control algorithm are given in detail. In the simulation the characteristics of objects were described by equations with different degrees of nonlinearity whose form was unknown. Equation form in the process of active accumulation of information was automatically restored on the base of input and output process variables measurements. The above computational experiments confirmed the possibility of using non-parametric algorithms to control nonlinear systems.

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This article describes the implementation of an electronic device capable of taking images written on boards. These images are stored, processed, and edited. This process extracts the necessary information to reproduce digitally the text on the boards. A Single Board Computer (SBC) Raspberry Pi was used, allowing the capture, rendering, and editing of the images. The images were obtained using the micro camera made for Raspberry Pi, which uses serial communication to capture images.

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Abstract:

The history of the world during the pandemic era shows a worse kind of treatment to the effected people. The year 2020 is known as a terrifying year due to pandemics in the world. It badly exposes the healthcare system’s weakness especially in the developing countries like Pakistan. Ambulance services played a major role in transporting affected people during pandemics. However, an independent survey shows that around 130 million people have very limited access to these facilities in Pakistan. The majority of the population of Pakistan lives in remote and rural areas and is deprived of these services. In this regard, remote monitoring of patients while they are in transit is very crucial. Considering the importance of providing better healthcare services to patients, we propose a model for remote patient monitoring systems (RPMS) integrated with emergency services in Pakistan. This healthcare model continuously keeps track of people including patients and nearest ambulances (the in-context emergency service and the key resource) for helping patients by transporting them to the appropriate healthcare center, as per needed assistance on the go. It helps reducing response time and yet increasing golden time by directly engaging the ambulance from the nearest location (using spatial and temporal features) and bypassing the call center to save the inevitable consumption of time shattered by conventional method. The represented model may enhance the availability of emergency healthcare facilities by reducing service time and allow efficient use of resources.

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