Desirable Limits Research Articles

Ecology of Lakebed in Relation to Benthic Organisms in Sasthamkotta Lake in Southern Kerala, India

Sasthamkotta Lake is the drinking water resource to Kollam city and suburban areas.The lake is designatedas Ramsar site since November 2002. The present study aims to assess the sediment quality and proportionof sediment-dwelling organisms in the lake. The physicochemical characteristics of sediment were withinthe desirable limit. Sediment particle size distribution showed that they have higher percentage of clay(clay > silt > sand). Order Diptera is dominant group in Sasthamkotta Lake. Phaenopsectra sp. is the abundantorganism accounting to about 97.927% in the total of benthic invertebrates. The study revealed that thelakebed is suitable for the survival of benthic organisms and maintains a healthy aquatic ecosystem.

Assessment of human health risk arising due to fluoride and nitrate in groundwater: a case study of Bhokardan tehsil of Maharashtra

Change in drinking water quality causes significant impacts on human health. Current research aims to identify the risk arising for infants, children, and adults due to the elevated concentration of nitrate and fluoride in groundwater. Groundwater samples from dug wells (100 samples) and bore wells (90 samples) were collected across the Bhokardan tehsil in December 2018. The physicochemical parameters like pH, EC, salinity, TDS, Nitrate, and Fluoride were analyzed. In most Bhokardan tehsil, NO3 concentration (45 mg/l) in bore well samples falls within the desirable limit. Still, in the case of dug wells, average nitrate is beyond the BIS permissible limits. 77% and 15.6% samples from dug and bore wells exceed the allowable limit (1.5 mg/l) of fluoride in drinking water. It is observed that in bore well samples, nitrate and fluoride depicts the highest risk to children (Avg. 1.44 and 1.88) as the average value is above critical value, i.e., 1 followed by infants (Avg. 1.06 and 1.64) and adults (Avg. 0.94 and 1.22) for the nitrate health risk. The highest THQ value for nitrate (4.81) and fluoride (2.42) was recorded for children. This analysis will help policymakers and practitioners develop policies at the administrative (tehsil) level to evaluate and monitor human health implications.

The Influence of Boron Carbide on the Mechanical Properties and Bonding Strength of B4C/Nickel 63 Coatings of Brake Disc

Metal-based ceramic composite laser cladding offers substantial compensations in enhancing brake disc surface characteristics. Laser cladding was utilized to combine B4C powder (10–40%) with Ni 63 powder to make Boron Carbide (B4C)/Nickel 63 composite coatings. For the subsequent experiments, the specimens were ground and polished. Bonding strength, fracture toughness, and residual stress were examined with the B4C content. The fracture morphologies were checked using a scanning electron microscope (SEM). It was observed that the bonding strength of various coatings might approach 175 MPa. Best bonding was observed when the B4C level was between 15% and 30%. The porousness of the coating continuously raised as B4C content increased. The coating’s maximum permeability was 5.6% after the B4C level reached 30%. As the B4C level in the coating grew, the coating’s compression resistance decreased. The bonding strength was within desirable limits, and compression resistance was consistently strong. The material bending strength increased when the B4C materials were reduced below 35%; at this level, the bending strength was highest. The bending strength was covered by the optimal range of bonding strength. Good bonding strength and mechanical characteristics were achieved when B4C content was 20% to 30%. The 20% B4C coating had the smoothest fracture morphologies and the strongest bonding strength, making it the most stable. For the estimation of total matrix deformation and corresponding coating stress on coated brake discs, Ansys software was utilized to create a static structural model.

Comparison of blood collection tubes for 29 biochemical analytes in pediatric patients with central venous catheters

BackgroundPediatric cancer patients undergoing chemotherapy or radiation therapy generally require a central venous catheter (CVC). However, serum drawn from CVCs has several drawbacks for use in routine chemistry tests. Biochemical analytes were evaluated using heparin plasma instead of serum to maintain turnaround time and to prevent problems caused by micro-clot formation or delayed clotting time. MethodsVenous blood samples from 52 pediatric oncology patients with chemoports or Hickman catheters were collected in serum separating tubes (SSTs) and lithium heparin tubes (LHTs). A total of 29 parameters were analyzed on a Cobas c702 (Roche Diagnostics, Mannheim, Germany). Passing-Bablok regression and Bland-Altman difference plots were used for statistical analyses. ResultsWhen the mean value of each analyte measured from LHT was compared with those from SST, percentage bias was within the desirable bias limit in most of the analytes. However, albumin, potassium, and inorganic phosphorus showed a negative constant bias of −3.0%, −5.3%, and −1.6%, respectively, and total protein showed a positive constant bias of + 3.8%. ConclusionsThe use of LHTs for sample collection from pediatric patients with CVCs could be helpful for routine chemistry analyses. The results of potassium and total protein should be interpreted with consideration of the difference between serum and plasma samples.

Fungus-Based MnO/Porous Carbon Nanohybrid as Efficient Laccase Mimic for Oxygen Reduction Catalysis and Hydroquinone Detection.

Developing efficient laccase-mimicking nanozymes via a facile and sustainable strategy is intriguing in environmental sensing and fuel cells. In our work, a MnO/porous carbon (MnO/PC) nanohybrid based on fungus was synthesized via a facile carbonization route. The nanohybrid was found to possess excellent laccase-mimicking activity using 2,2′-azinobis (3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS) as the substrate. Compared with the natural laccase and reported nanozymes, the MnO/PC nanozyme had much lower Km value. Furthermore, the electrochemical results show that the MnO/PC nanozyme had high electrocatalytic activity toward the oxygen reduction reaction (ORR) when it was modified on the electrode. The hybrid nanozyme could catalyze the four-electron ORR, similar to natural laccase. Moreover, hydroquinone (HQ) induced the reduction of oxABTS and caused the green color to fade, which provided colorimetric detection of HQ. A desirable linear relationship (0–50 μM) and detection limit (0.5 μM) were obtained. Our work opens a simple and sustainable avenue to develop a carbon–metal hybrid nanozyme in environment and energy applications.

Physico- Chemical Assessment of Tube wells Water Quality of Pilani Town District Jhunjhunu, Rajasthan, India.

The water has become an emotive issue with the people. The paper presents groundwater quality assessments of Pilani Town District Jhunjhunu, Rajasthan India. The water samples were collected from 10 open wells, tube wells and hand pumps in Pilani. Ground water is increasingly being sought as a source of drinking water due to the scarcity, non-availability and bacteriological pollution of surface water. This paper describes the important results of the Physico-chemical Assessment of the ground water samples of the open wells, tube wells and hand pumps of the urban areas in Pilani, District Jhunjhunu of Rajasthan. The different parameters determined are pH, TDS, fluoride, chloride, nitrate, sulphate, total alkalinity and total hardness. It has been observed that nitrate values are higher compaired to ICMR standards. Other parameters were found within desirable limits. The interesting fact is that the nitrate alone is making ground water unfit for drinking.

Physico-Chemical Studies of Ground Water Quality of Chirawa, Buhana and Surajgarh Tehsil of Jhunjhunu District. Rajasthan (With Special Reference to Fluoride)

In Present Paper the Physicochemical Studies of ground water of Chirawa, Buhana and Surajgarh tehsil of Jhunjhunu district have been studied. Water samples from the ground water of villages, colonies, school, hospitals and railway station were collected and analysed for physico- chemical parameters like ammonia, alkalinity, pH, electrical conductivity, turbidity, TDS, Total hardness, and concentration of ions like chloride, fluoride, nitrate, sulphate, sodium, potassium, phosphorus, some heavy metal like as Mn and Fe. It has been observed that all parameters were found within desirable limit compared to BIS, but fluoride, potassium, and sodium values are higher compared to WHO. The interesting fact that phosphorus, iron and manganese were not found in any ground water samples. Only fluoride, potassium and sodium are making ground water unfit for drinking.

Fluoride occurrence, health issues, and removal using adsorption process

Safe drinking water is a key ingredient to a sustainable life for mankind. Fluoride is considered a micronutrient required in a minute quantity for the proper functioning of bones and teeth in humans. However, its higher concentration could lead to toxic effects on skeletal and dental health. The amount of fluoride required can be easily achieved through the consumption of vegetables, cereals, and drinking water (within desirable limits). Fluoride beyond the limits in groundwater has become a major issue in most of the states of India while Rajasthan has been considered as most severely affected with fluorosis where all the districts were reported with a high concentration of fluoride in groundwater. Adsorption technique was recently developed as a low-cost method that can potentially remove excess fluoride from groundwater. Numerous adsorbent developed so far has been discussed in this review to explore their potential for defluoridation. The ability of this method greatly depends on the development of adsorptive materials. It was found after the literature survey that several types of adsorbent using chemicals as well as vegetative waste have been developed and studied to quantify the removal capacity of fluoride from water. However, their utility on the water is still needed to be studied to explore these adsorbents for commercial use leading to the improvement in water quality.

WATER QUALITY ASSESSMENT OF KAYAMKULAM LAKE, KERALA, INDIA

The present investigation was carried out in Kayamkulam Lake near National Thermal Power Corporation (NTPC) industrial area, Alappuzha district, Kerala, India, with regard to various Physico -chemical parameters like surface water Temperature, pH, Total Alkalinity (TA), CO2, Dissolved oxygen(DO), Chloride, Total Hardness (TH), Calcium, Phosphate, Sulphate, Nitrate Biochemical Oxygen Demand(BOD), Chemical Oxygen Demand (COD), Silicate and heavy metals viz., Iron, Lead, Zinc, Cadmium and Copper. Monthly variations in physico- chemical parameters were recorded. Surface water Temperature varied from 29.6 to 37ºC, the pH values decreased up to 6.3 and it reached below the permissible limit at site II. The Total Alkalinity of lake water ranged from 20 to160 mg/l and it reached beyond the permissible limit of 120 mg/l. The DO falls up much lower than the desirable limit at site II. The average value of BOD reached beyond the permissible limit at site II . The chloride concentration varied from 47 to1127 mg/l and concentration reaches beyond the permissible limit. The TH of the lake water ranged from 26 to1112 mg/l. Sulphate concentration of the lake water lie within the permissible limit. Heavy metal analysis revealed that sites II and III are much polluted than site I .Results of the study showed that the lake water is not suitable for irrigation and domestic purpose without proper treatment. The results are discussed in the text.

Hydrochemistry and Quality Assessment of Surface Water in Oba Dam, Ogbomoso, Southwestern Nigeria

Hydrochemistry of the surface water in Oba Dam, Ogbomoso was investigated to determine the chemical characteristic and evaluate the water quality for drinking, domestic and agricultural usage. Twenty selected water samples collected at different points within the reservoir were analysed for pH, Electrical Conductivity (EC), Total Dissolved Solids (TDS), Total Hardness (TH) and major ions (Na+, K+, Mg2+, Ca2+, Cl-, NO3-, SO42-, HCO3). The pH values (6.5-7.9) of the samples suggest circumneutral to weakly alkaline nature of the water in Oba Dam. The cations are dominantly Na+ and K+, while the anions are mainly NO3-, Cl- and SO42-. The plot of the chemical data in Piper diagram revealed the water samples as Na-K-Cl water facie suggesting that the water chemistry is being controlled mainly by anthropogenic inputs. Comparing the analysed water samples with WHO and Nigerian water quality standards shows that all the chemical parameters were within the desirable limits for drinking purpose. Similarly, the computed water quality index (WQI) values (15-21) for the studied water samples suggest excellent quality for drinking and domestic purposes. Calculated parameters like sodium adsorption ratio (SAR), percent sodium (%Na) and Keller index (K1) reveal that most of the analysed water samples are suitable for irrigation usage. However, higher Na+ content of few samples restrict the suitability for irrigation purposes. Therefore, this calls for regular monitoring of sodium contents to ascertain suitability for agricultural irrigation.

Destructive test study of the flexural load capacity of a full-scale reinforced concrete T-girder strengthened by externally prestressed CFRP plates

With the upgrade of the transportation capacity of some existing freight tracks to heavy-haul railways in China, there is increased use of heavy-haul trains with larger axle loads and traction masses than in the past. The existing railway bridges not only bear the increased loads of heavy-haul trains but also experience much more loading times. This situation greatly affects the normal use and even the bearing capacity of reinforced concrete bridges and leads to concrete cracks and decreased flexural rigidity of the girders. As a result, the ultimate bearing capacity and operational safety of girders must be reasonably strengthened. Two reinforced concrete T-girders with a span of 12 m were demolished after 20 years of service. One of the T-girders, without any treatment, was selected for the destructive bending test, and the failure process and actual ultimate bearing capacity were obtained. The other girder was strengthened by the tensioning of prestressed carbon fiber reinforced plastic (CFRP) plates which showed the advantages of high tensile stress more than 2600 MPa, light mass, anti-corrosion and good resistance to durability. Then a destructive comparative bending test was performed to verify the strengthening effect. The research results showed that the actual ultimate flexural load capacity of the unstrengthened T-girder was 1.58 times the original design load capacity. After the T-girder was strengthened by prestressed CFRP plates, the cracking moment and actual ultimate flexural load capacity were 30.5% and 16.4% higher, respectively, which could decrease the cracking degree and deflection-span ratio of the T-girder under the operating conditions of heavy-haul trains. The strengthened T-girder showed a desirable serviceable limit state and ultimate flexural bearing capacity for KM98 trains with 300 kN axles.

Enhancement of Power Quality in Power Distribution Systems Using FC- TCR Based Compensation Systems

The development of modern electronic systems and increasing number of application areas (computers, office equipment, rectifiers, converters, speed control devices, uninterruptible power supplies, switched power supplies) has led to harmonic generation and reduced energy efficiency. The majority of loads are inductive in nature and the draw of reactive power has increased in networks and transmission lines resulting in problems with power quality. In addition to efficient power flow in transmission systems, there is also a need to compensate for the reactive power flow in order the meet the requirements of the load and system. As an alternative to traditional solutions, FACTS (Flexible Alternating Current Transmission Systems) has been developed in order to operate electrical systems efficiently and improve stability and power quality. Technological applications such as SVC, STATCOM, SSSC and active harmonic filter are becoming widespread in order to improve power quality. In this study, applications within the scope of FACTS systems are explained and analysis of a fixed capacitor-thyristor controlled reactor (FC-TCR) to improve power factor is discussed. A circuit model of the FC-TCR is developed as a simulation and used to investigate how power factor may be kept within desired limits by adjusting the firing angle of the thyristors under different load conditions. A comparative evaluation has been carried out to determine the effect of FC-TCR by presenting results before and after the load compensation process is applied. From the simulation it is observed that reactive power compensation can be achieved even for varying linear loads.

Impact of acid mine drainage on groundwater hydrogeochemistry at a pyrite mine (South China): a study using stable isotopes and multivariate statistical analyses.

Combining environmental isotope analysis with principal component analysis can be an effective method to discriminate the inflows and sources of contamination in mining-affected watersheds. This paper presents a field-scale study conducted at an acid mine drainage (AMD)-contaminated site adjacent to a pyrite mine in South China. Samples of surface water and groundwater were collected to investigate transport in the vadose zone using stable isotopes of oxygen (δ18O) and hydrogen (δD) as environmental tracers. Principal component analysis of hydrogeochemical data was used to identify the probable sources of heavy metals in the AMD. The heavy metal pollution index (HPI) was applied to evaluate the pollution status of heavy metals in the groundwater. The groundwater associated with the Datai reservoir was recharged by atmospheric precipitation and surface water. On the side near the AMD pond, the groundwater was significantly affected by the soluble metals produced by pyrite oxidation. The concentrations of some metals (Al, Mn, and Pb) in all of the samples exceed the desirable limits prescribed by the World Health Organization (Guidelines for drinking-water quality, 4th edn. World Health Organization, Geneva, 2011). Among them, the concentration of Al is more than 30,000 times higher than the desirable limits prescribed by the World Health Organization (2011), and the concentration of Mn is more than 3000 times higher. The HPI values based on these heavy metal concentrations were found to be 10-1000 times higher than the critical pollution index value of 100. These findings provide a reference and guidance for research on the migration and evolution of heavy metals in vadose zone water in AMD-contaminated areas.

Early stage evaluation of colon cancer using tungsten disulfide quantum dots and bacteriophage nano-biocomposite as an efficient electrochemical platform

BackgroundRecently, biosensors have become popular analytical tools for small analytes due to their high sensitivity and wide analytical range. In the present work, development of a novel biosensing method based on tungsten disulfide quantum dots (WS2 QDs)-Au for rapidly and selectively detecting c-Met protein is introduced. As a proof of concept, M13 bacteriophage-based biosensors were used for the electrochemical detection of c-Met protein as a colon cancer biomarker.MethodThe M13 bacteriophage (virus), as the biorecognition element, was immobilized on glassy carbon electrodes which were modified by WS2 QDs-functionalized gold nanoparticles. The stepwise presence of the WS2 QDs, gold nanoparticles, and immobilized phage on glassy carbon electrodes were confirmed by scanning electron microscope (SEM) and square wave voltammetry (SWV) technique.ResultsThe designed biosensor was applied to measure the amount of c-Met protein in standard solutions, and consequently the desirable detection limit of 1 pg was obtained. Finally, as a proof of concept, the developed platform was used for the evaluation of c-Met protein in serum samples of colon cancer-suffering patients and the results were compared with the results of the common Elisa kit.ConclusionsAs an interesting part of this study, some concentrations of the c-Met protein in colon cancer serum samples which could not be determined by Elisa, were easily analyzed by the developed bioassay system. The developed bioassay system has great potential to application in biomedical laboratories.Graphical

Monolithic Silicon-Based Photovoltaic-Nanoplasmonic Biosensor With Enhanced Limit of Detection and Minimum Detectable Power

On-chip, fully integrated electrical readout nanoplasmonic biosensors are suitable technology for the increasing demands of compact, portable, cost-efficient, and sensitive biosensors. In this paper, an ultra-compact photonic biosensor based on plasmonic nanostructure integrated with a PIN photovoltaic detector in a single chip is presented. The refractive index of different biosamples results in a shift in the surface plasmon resonance wavelength of the biosensor, and the PIN photovoltaic detector measures the intensity of transmitted light from the photonic structure at the plasmonic resonance wavelength. The biosensor shows a linear optical response of 354 nm/RIU and electrical sensitivity of about 16.9 mA/W.RIU for a wide range of biosamples. The PIN photovoltaic ultra-low dark current enables an extremely desirable limit of detection of 3 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−8</sup> RIU and minimum detectable power of −54 dBm for the biosensor. Moreover, a simple light-emitting diode is used as the light source in the biosensor's structure, which reduces its complexity and price by eliminating any extra optical setups and beam shapers. The presented structure is an important step forward for the realization of practical and handheld lab-on-chip nanophotonic biosensors, which leads to eliminating large clinical laboratories.

“Spatial Data Analysis for Ground Water Quality Assessment With Special Reference to Fluoride” - A Case Study of Dhar District, Madhya Pradesh, India

Water is a prime natural resource and physiological necessity to mankind. Therefore, drinking water must not carry harmful chemicals as well as biological contaminants for the well-being and human health. Some of the chemicals like Fluoride, Iron, Arsenic, Cadmium, Chromium, Lead, selenium, and Nitrate in water may produce serious physiological changes when exist beyond permissible concentration.&#x0D; &#x0D; The Aim of the study was to create spatial map for drinking water purpose for Dhar district, MP. The ground water quality data were collected from PHED, M.P. and IMIS (Ministry of Drinking water &amp;amp; Sanitation) Website,Government of India. The GWQ layers were created&amp;nbsp; separately for each element for Pre-Monsoon and Post-Monsoon period from the well point layers with interpolation technique. Each element wise layer has been categorised into `three catagories (1) potable water in Desirable limits (2) Potable water in permissible limits (3) non-potable ground water, as per BIS standard, 2015. The Union of eight element layers of each pre-monsoon and post-monsoon has been done and integrated pre-monsoon and Integrated post-monsoon Ground Water Quality (GWQ) map have been prepared and after the Union of these two maps, the Final ground water quality map has been prepared. It was concluded from the study, that multiple parameters are affecting the quality of ground water in Dhar district and particularly excess Fluoride, Nitrate, Total Hardness (as Caco3), Iron, pH, and Total Dissolve solids are prevalent in the area. About 69.66% Habitation of Dhar district is severely affected mainly by excess of Fluoride, Nitrate &amp;amp; Total Hardness (as Caco3), pH &amp;amp; Iron(Fe) &amp;amp; It is observed that about 70.51% area of Dhar district has been affected in terms of Ground Water Quality.

A Modified Non Electrical Filter for Decontamination of Iron Rich Water for Rural Application

A non-electrical filter is designed to cater the need of providing iron free water in forward and rural areas. The features of the unit are equipped with the aeration system and activated sand chemically coated by iron oxide as catalytic and filtering media which can bring down iron concentration from 12 mg/L to desirable limit. It increases the pH of water from acidic to pH above 7. This is in contrast to some indigenous water filter which existed in the North Eastern India that tend to remove iron below 4 mg/L. The modified filter is effective in reducing excess total dissolved solids (TDS) from drinking water. All other physical parameters found to be within the prescribed limit. It can give iron free water with output capacity of 25L/hr. The added advantage of the unit is the provision for back washing of the filter media and collection point of the precipitated iron at the lower bottom of the tank for safe discharge.

P-Type Semiconduction in Oxides with Cation Lone Pairs

Semiconducting oxides are valuable as thin-film displays or solar cell electrodes and are recently of interest as back-end-of-line devices. There are numerous high-mobility n-type semiconducting oxides, but there is a lack of p-type oxides with similar mobility. This led to a search for additional p-type oxides using high-throughput calculations. We find that many of these proposed oxides possess cation s-like lone-pair states. The defect energies of some of these oxides are calculated here in detail. SnTa2O6 is found to be promising p-type oxide based on its low effective hole mass owing to its cation lone-pair character, wide stability range, and absence of compensating native defects. This leads to a desirable p-type doping limit range, which includes the valence band edge, but other oxides with structures more closely based on perovskite configuration are more n-type rather than p-type. The experimentally observed p-type conductivity in related niobium compounds is also discussed. The valence band edge of the disordered SnTa2O6 phase has a mixed O(p)–Sn(s)–O(p) character; thus, it is relatively insensitive to disorders, indicating that it could also make an effective p-type amorphous semiconductor.

Groundwater quality assessment for sustainable drinking purpose in some blocks of district Ludhiana

The Groundwater is the purest form of water which is available for drinking and irrigation purpose. Groundwater quality varies depending on a variety of factors such as the geology of a certain location, the depth of the water table, the composition of dissolved salts, seasonal fluctuations, and so on. The dumping of untreated industrial effluents straight into rivers and streams is the primary cause of water pollution, resulting in significant levels of pollution in both surface and groundwater. People are more susceptible to stomach and digestive system disorders, such as skin problems, nail problems, diarrhea with fever, and dysentery, as a result of dirty water used for drinking and irrigation. Groundwater is becoming more vital for social and economic activity as the human population grows rapidly. Samples were collected from the areas of Ludhiana district to evaluate the groundwater quality. In this study it is found that the groundwater was contaminated with microorganisms. In some areas the total dissolved solids (TDS), Total Hardness and Total Alkalinity were higher than the permissible level (IS 10500:2012). The concentration of Chloride is below the desirable limits. Also in most of the areas the magnesium concentration is below the Desirable limits. Anthropogenic activities, agricultural activities, and leaching may all contribute to higher Alkalinity and total hardness values in these locations.

Removal of phenol by liquid-liquid extraction from pharmaceutical wastewater

Phenol is a highly toxic chemical tohumansand aquatic biodiversity. The desirable limit according to [Bureau of Indian Standards] for phenol in drinking water is 0.001 mg/L. Several industries and anthropogenic activities are responsible for entry of organic compounds in natural water resources. The study was carried out for the removal of phenol present in the wastewater by liquid-liquid extraction process. In this process toluene is used in capacity of solvent to extract phenol from wastewater. Chemical oxygen demand of wastewater was determined before and after extraction, to check the efficiency of treatment. The laboratory experiments were carried out on 5% aqueous solution of phenol. Chemical oxygen demand was measured at different pH: 4,5,6,7 and varying % of toluene: 20, 30, 40. After extraction with organic solvent, two separate layers were formed; one of toluene + phenol (organic) and the other of water + some amount of phenol (aqueous). Optimum experimental conditions were found at 7 pH and 20% toluene concentration. At these conditions, the highest 60% phenol removal was obtained for 5% aqueous solution of phenol and 68% phenol removal was obtained for actual pharmaceutical wastewater.