Pakistan Journal of Scientific & Industrial Research Series A: Physical Sciences

Effect of Xanthan Gum Content on the Rheological Behaviour of Mayonnaise

2024-02-27T09:01:00+00:00

This study explores the effect of various concentrations of Xanthan gum on the rheological behaviour of commercial mayonnaise. The various concentrations of Xanthan gum, ranging from 0.1 to 0.5% based on the weight of the mayonnaise which were mixed in the commercial mayonnaise via a high overhead stirrer at room temperature. The rheological characterizations were carried out on a Brookfield viscometer. Using Mitschka's method, the recorded data was changed into rheological parameters. Three rheological models, namely the Power-law model, Bingham model and Herschel-Bulkley model, used to determine the flow parameters of the samples. All the samples showed shear thinning behaviour at least in the shear rate used in this study. According to the goodness of fit (regression coefficient), the power law model was the best for determining flow parameters. It was observed that the consistency viscosity (K) increases with an increase in Xanthan gum concentration, at least for the concentration ranges used in this research. The higher value of K indicates that the mayonnaise becomes thick with Xanthan gum and will require higher yield stress to start flow. It was interesting to note that at 0.1% Xanthan gum concentration, the power index reached a plateau value of 0.1135.

Treatability Study of Phenol by Using Dracaena sanderiana Based Activated Carbon from Synthetic Aqueous Solution

2024-02-27T11:46:19+00:00

Phenols in industrial wastewater are a great threat to human and aquatic life. For removing such a hazardous pollutant, adsorption is one of the efficient techniques. The current study highlights the preparation of Dracaena sanderiana based activated carbon and its characterization, physical and chemical activation and application. At the lab scale variable doses of activated carbon (AC) and its modified forms such as acid treated and furnace treated were applied for the removal of phenol from synthetic solution. The highest removal efficiency was observed at a dose of 0.2 g, 120 rpm and neutral pH (7) with a contact time of 1 h for acid treated AC. For optimization of this process, the addition of anthracite coal to acid treated AC resulted in the enhancement of its adsorbability. The FT-IR spectrum has provided ample information regarding functional groups responsible for the adsorbent after treatment. This study concludes that the adsorption of phenol through AC in combination with anthracite coal is an effective treatment option.

Exploring the Effect of Sintering Temperature on Hydroxyapatite Derived from Egg Shells

2024-02-27T12:04:06+00:00

The term hydroxyapatite Ca5(P04)3(0H) is naturally occurring mineral and chemically identical to the mineral constituent of bones and solid tissues of mankind and mammals used for bone grafting, augmentation in maxillofacial surgery and in orthopedics as space filling material. However, the brittleness of pure HA materials narrows its application only to low-load bearing applications. Generally, for the improvement of the mechanical properties and the structural one, hydroxy apatite is subjected to the sintering process. Thus, an optimization of the mechanical properties and micro structure of hydroxy apatite through a suitable choice of sintering parameters is under investigation. This paper presents the effect of sintering temperature on mechanical properties of hydroxy apatite compacts. A chemical precipitation method was successfully employed to prepare hydroxy apatite powder from waste egg shells. The eggshell derived HA is a cost effective bio-ceramic for biomedical applications and an effective material recycling technology. HA derived from egg shells and 5% organic additive was cold uniaxially pressed at 2500 psi for 3 min isothermal hold. The resulting compacts were sintered at different temperatures from 900-1100 °C for dwell time of 2 h. The samples were characterized by analyzing micro structural analysis, compressive strength, porosity and radial shrinkage. Compressive strength and porosity was increased with increase in sintering temperature, while radial shrinkage was decreased with increasing sintering temperature. Structural analysis showed that inter connected pores were developed and a material with inter connected pores is thought to be a good candidate as scaffold material.

Drinking Water Quality Improvement by Removal of Salinity Using Wetland

2024-02-27T12:50:04+00:00

The majority of developed countries suffer from water contamination because they have no control over the discharge of chemical waste into the water. In contrast, developing countries contaminate clean from water due to the discharge of agricultural waste. Contaminated water is a threat to human life as it causes many waterborne diseases that can be prevented by making efforts at an individual level. An effort has been made in this research to find an alternative method to treat water using wetlands. A further attempt has also been made to reduce total dissolved solids from water using wetlands. The development of constructed wetlands that can effectively treat saline water is the goal of this study. Because they can thrive in a salty environment, phragmites have been planted in every constructed wetland (CW). Eight pots were developed and worked under conditions reenacting diversely built wetlands. A relative report shows that total dissolved solids (TDS) content between 1000-3000 ppm in the water in flow developed wetland with in growth estate having gel soil gives the most elevated decline in conductivity of saline water at gushing. For effluent water with a salinity content of 1500 ppm, this artificially assembled system is extremely effective. As a result, this study demonstrates that the construction of a wetland using gel soil and carbon nanotube will offer an effective method for lowering water salinity.

Surface Response Evaluation of Agro-waste for Efficient Adsorption of Phenol from Wastewater

2024-02-27T13:05:25+00:00

The feasibility of using modified activated carbon (AC) obtained from discarded agricultural waste, including carrot residues, sawdust and orange pulp for phenol removal from aqueous solution was studied. The results showed maximum removal was found in sawdust AC compared to orange pulp AC and carrot waste AC, 76%, 73% and 72% respectively. The maximum result of sawdust AC was achieved at concentration of 10 mg/L, pH 4.5, 1.5 h and 2 g dose whereas for orange pulp AC and concentration of 10 mg/L, pH 7.5, 2 h and 2 g dose of orange pulp AC. The ANOVA analysis was performed to check the suitability of central composite design and the quadratic model was found to be appropriate. This study concluded that natural, low-cost bio-sorbent derived from sawdust, orange pulp and carrot residues may be useful for phenol removal.

Sick Building Syndrome Study of a Historical Place in Karachi

2024-02-27T13:11:57+00:00

Sick building syndrome (SBS) is characterized by a group of common symptoms that occur inside the building like working offices, schools, malls or industries. It causes many adverse health effects due to tightly packed indoor environment. This is the first study done at the historical place of Karachi pertaining to SBS. A questionnaire based survey was conducted in Empress market, Karachi in October 2018 to find out the negative impact on human health as well as to give awareness about SBS to workers. This building consists of almost 280 shops and workers. The workers suffer from common health diseases like headache, fatigue and dryness of the throat. Congested areas, no ventilation, poor design and heavy traffic were observed. Fans were the only source of ventilation. SBS effects can be reduced by the good ventilation source, proper cleaning system, building maintenance and proper bimonthly checkup of the workers.

Road Traffic Accidents (RTAs) in Bahawalpur City, Pakistan: A Comparative Injury Analysis

2024-02-27T14:29:44+00:00

Road traffic accidents (RTAs) hold a top and rising contributor to the regional and global casualties and deaths particularly in countries like Pakistan. The main objective of this research was make a comparison of the RTAs took place in Tehsil Bahawalpur city and to identify the main causes and victims during 2015-2019. Data is collected from Punjab rescue emergency service 1122 Bahawalpur and manipulated and re-arranged as per objective of the study. It is analyzed in SPSS 17 by applying descriptive statistics and Chi-square Test as an inferential statistics to find out the relationship of RTAs with selected variables. Results showed that, during the last few years the numbers of road traffic accidents are increased. The root causes of RTAs observed were including care lessness of drivers (42.22% and 43.10% in 2015 and 2019 respectively) over speeding (39.92% and 33.89% in 2015 and 2019 respectively) over taking and violation of traffic rules. Most of the victims in RTAs were drivers (32.89% and 34.91% in 2015 and 2019 respectively). The youngsters (aging 21-30) were the leading victims of 1,848 (29.14%) in 2015 to 2,410 (28.69%) in 2019 due to the ever increasing registrations of the motor bikes as the main source of RTAs (69.05% and 72.91% in 2015 and 2019 respectively). Most of the RTAs caused fractures and minor injuries (33.39% and 33.78% in 2015 and 2019 respectively). Chi-square results also show that there is close association between the care lessness and the bike accidents (P-value > 0.05). Lastly, the spatial hotspots identification maps of RTAs done with the aid of GIS visualize that severe accidents were occurred on cross roads, chowks and inter-city roads i.e. Hasilpur road, Yazman road, Ahmadpur road others. Lastly, it is hoped that this research would be beneficial for the society in many ways from understanding of the RTAs nature to adopting preventive measures.

Estimation of Correlation Between Electrical Conductivity, Solids and Hardness of Highway Stormwater Run-off

2024-02-27T16:25:47+00:00

A comprehensive understanding of pollutants of highway stormwater run-off is required for accurate prediction of various constituents and for planning and assessment of proposed or existing highway corridors. Besides the adequate availability of staff and laboratory equipment, regular monitoring and estimation of all constituents in highway runoff water is very difficult. Hence, alternate statistical methods for the comparison of constituents are highly appreciated. In this research work, an attempt was made to estimate the relationship between electrical conductivity (Ec), total dissolved solids (TDS), total suspended solids (TSS) and hardness of highway stormwater run-off to decrease the time and cost required for collection, testing and measurement of samples for quality data. Eight consecutive storm events were monitored during monsoon season from June to July 2019 and twenty-four stormwater samples were collected from an urban highway in Lahore, Pakistan and analyzed for pH, temperature (T), Ec, TDS, TSS and hardness to determine physiochemical properties of highway run-off water. After analyzing selected physiochemical parameters, regression-based predictive relationships were developed between these parameters. A strong linear relationship with a high coefficient of determination i.e., 0.97 was found between Ec and TDS, while the correlation of Ec with TSS and hardness is very poor having a weak coefficient of determination i.e., 0.49 and 0.76 respectively revealing the unreliability of developed correlations.

A Physical Reason Why Molten Lead-bismuth Alloy has Advantage of Being Used as a Potential Coolant for Fast Nuclear Reactors Design

2024-02-27T16:33:04+00:00

The development of new energy sources from nuclear energy is increasingly becoming the choice of many countries. One type of nuclear reactor that is promising to be developed in the future is a liquid lead-bismuth cooled fast nuclear reactor. The important use of this liquid bismuth eutectic (LBE) for coolant of fast nuclear reactor has long been a potential choice. The LBE with composition of Pb and Bi commonly used and about Pb 44.5wt% and Bi 55.5%wt. What is so special about this composition? This study seeks to see the physical reasons why the fast reactor nuclear design uses LBE with a composition of about Pb 44.5wt% and Bi 55.5%wt. From the result of the molecular dynamics simulation of iron in the LBE at a temperature of 1023K, it can be observed that the use of LBE liquid metal coolant with that composition caused the least damage effect (corrosion) to iron compared to using other compositions. It can be concluded from the calculation of the CNA values (Common Neighbour Analysis) of the iron structure in the LBE which shows that the crystal structure of iron in the LBE is the most stable for that composition. This simulation result is extraordinary because it explains the popular choice of the PbBi composition for the coolant candidate of fast nuclear reactors.

Covid 19 and Food Safety: Guidance for Preventive Techniques in Food Borne Diseases by Micro-organisms

2024-02-27T17:16:51+00:00

Surface hygiene is commonly measured as a part of the quality system of food processing plants but as the bacteria present are commonly not identified and their roles for food quality and safety are not known. Here, we review the identity of residential bacteria and characteristics relevant for survival and growth in the food industry along with potential implications for food safety and quality. Sampling after cleaning and disinfection increases the likelihood of targeting residential bacteria. The increasing use of sequencing technologies to identify bacteria has improved knowledge about the bacteria present in food premises. Overall, non-pathogenic gram-negative bacteria, especially Pseudomonas spp., followed by Enterobacteriaceae and Acinetobacter spp. dominate on food processing surfaces. Pseudomonas spp. persistence is likely due to growth at low temperatures, biofilm formation, tolerance to biocides and low growth requirements. Gram-positive bacteria are most frequently found in dairies and in dry production environments. The residential bacteria may end up in the final products through cross contamination and may affect food quality. Such effects can be negative and lead to spoilage, but the bacteria may also contribute positively, as through spontaneous fermentation. Pathogenic bacteria present in food processing environments may interact with residential bacteria, resulting in both inhibitory and stimulatory effects on pathogens in multi species biofilms. The residential bacterial population or bacteriota, which does not seem to be an important source for the transfer of antibiotic resistance genes to humans but more knowledge is needed to verify this. If residential bacteria occur in high numbers, they may influence processes such as membrane filtration and corrosion. The use of high temperatures to preserve and ensure the safety of food is based on the effect of microbial destruction. Thermal processing is one of the most widely used unit operations employed in the food industry and is frequency determined as a critical control point. This white paper covers the main science behind the unit operation and should be used to underpin the development and design of thermal processing steps type.