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The purpose of this paper is to evaluate the protective effects of Persian gum and gum Arabic on the survival of Lactobacillus plantarum subsp. plantarum PTCC 1896, Escherichia coli, Xanthomonas axonopodis, and Saccharomyces cerevisiae during freeze drying.

Cultures were harvested from the early stationary phase and enumerated after dilution according to the Milse Misra method. Bacterial suspensions were mixed with protective agents and frozen at –80°C before drying in a freeze dryer. Survival rates were determined both immediately during freeze drying and after 14 days of cold storage (at 4°C).

Compared to gum Arabic 5 and 10 percent (W/V) or skim milk 10 percent (W/V), Persian gum 1 percent (W/V) showed no significantly different effects on the survival of Lactobacillus plantarum subsp. plantarum PTCC 1896 (p<0.05). Similarly, no significant differences (p<0.05) were observed between Persian gum 6 percent (W/V), gum Arabic 6 percent (W/V), the combination of Persian gum 3 percent (W/V) and gum Arabic 3 percent (W/V), and skim milk 10 percent (W/V) in terms of their effects on the survival of Escherichia coli. Skim milk 10 percent (W/V) was, however, found to have significant (p<0.05) effects on the survival of Xanthomonas axonopodis and Saccharomyces cerevisiae. Statistically significant (p<0.05) effects were observed after 14 days of cold storage (4°C) by Persian gum 6 percent (W/V) on the survival of Escherichia coli and by gum Arabic 6 percent (W/V) on the survival of Xanthomonas axonopodis and Saccharomyces cerevisiae. It was concluded that protective agents could be replaced by Persian gum for its effect on the survival rate of Escherichia coli and by skim milk for its effects on the survival of Xanthomonas axonopodis and Saccharomyces cerevisiae. Persian gum 6 percent (W/V) seemed to be the best protective agent for Escherichia coli during 14 days of its storage as gum Arabic 6 percent (W/V) seemed to have the same performance for Xanthomonas axonopodis and Saccharomyces cerevisiae. Persian gum 1 percent (W/V) was also found an alternative protective agent for the freeze drying of Lactobacillus plantarum subsp. plantarum PTCC 1896.

As Iranian Persian gum is cheap due to its wide availability and seems to have effects similar to those of gum Arabic and skim milk at low concentrations, it may be considered a good candidate for industrial applications.

Personal protective clothing (PPC) enables people to work in hazardous environments, but PPC can have a detrimental effect on worker performance. Predicting garment effects on worker performance is difficult because quantitative relationships among garment properties and human responses are not known. Presents a systematic structure for studying the relationships among garment properties and their immediate effects on the worker. Using a survey of 118 studies, previous work was categorized according to garment parameters and dependent measures. Except for studies of heat stress, most of these studies compared competing garments or simply measured physiological response, rather than relating these effects to garment attributes. Such results are seldom transferable to other clothing systems or tasks. Proposes a conceptual model based on this systematic structure. Introduces garment impediment indices (GIIs) as response functions of garment attributes, and offers an approach for developing quantitative models of PPC effects on worker performance.

The purpose of this paper is to study the combined effects of moisture and radiation on thermal protective performance of protective clothing exposed to low level radiation.

Using a sweating manikin, the effect of radiation and moisture on heat and moisture transfer was initially analyzed under the dry manikin with sweating rate of 100 g/(m2h) exposed to 2.5 kW/m2, and then studied at 200 and 300 g/(m2h) exposed to 2 and 3 kW/m2, respectively. Finally, the combined effects of thermal radiation and moisture were predicted by fitting the relationships among heat loss and wet skin surface temperature, with the sweating rate and radiation intensity.

The results show that the heat loss and the wet skin surface temperature are affected by the combined effects of moisture and radiation, with two distinctly different trends. Heat loss from the manikin is increasing with the sweating rate, and decreasing with thermal radiation intensity. However, the wet skin surface temperature has an opposite situation.

Two filling equations are given to present the relationships among heat loss and wet skin surface temperature, with the sweating rate and radiation intensity. With these two equations, the heat loss and the wet skin surface temperature when exposed to radiation can be predicted by only measuring the mean radiant and ambient temperatures and controlling the sweating rate.

The purpose of this study is to determine the effect of ventilation openings and fire intensity on heat transfer and fluid flow within the microclimate between 3D human body and clothing.

On account of interaction effects of fire and ventilation openings on heat transfer process, a 3D transient computational fluid dynamics model considering the real shape of human body and clothing was developed. The model was validated by comparing heat flux history and distribution with experimental results. Heat transfer modes and fluid flow were investigated under three levels of fire intensity for the microclimate with ventilation openings and closures.

Temperature distribution on skin surface with open microclimate was heavily depended on the heat transfer through ventilation openings. Higher temperature for the clothing with confined microclimate was affected by the position and direction of flames injection. The presence of openings contributed to the greater velocity at forearms, shanks and around neck, which enhanced the convective heat transfer within microclimate. Thermal radiation was the dominant heat transfer mode within the microclimate for garment with closures. On the contrary, convective heat transfer within microclimate for clothing with openings cannot be neglected.

The findings provided fundamental supports for the ease and pattern design of the improved thermal protective systems, so as to realize the optimal thermal insulation of the microclimate on the garment level in the future.

The outcomes broaden the insights of results obtained from the mesoscale models. Different high skin temperature distribution and heat transfer modes caused by thermal environment and clothing structure provide basis for advanced thermal protective clothing design.

The purpose of this paper is to examine the extent to which negative online risk experiences (information breaches, explicit content exposure, cyberbullying and sexual solicitations) cause post-traumatic stress disorder (PTSD) symptoms in adolescents. The study also explores whether teens’ short-term coping responses serve to mitigate PTSD or, instead, act as a response to stress from online events.

The study utilized a web-based diary design over the course of two months. Data were analyzed using hierarchical linear modeling with repeated measures.

The study confirmed that explicit content exposure, cyberbullying and sexual solicitations (but not information breaches) evoke symptoms of PTSD. Analyses also indicated that teens engage in active and communicative coping after they experience post-traumatic stress, regardless of risk type or frequency.

The authors found that teens took active measures to cope with online risks soon after they felt threatened (within a week). Actively coping with stressful situations has been shown to enhance adolescent resilience and reduce long-term negative effects of risk exposure. If these early coping behaviors can be detected, social media platforms may be able to embed effective interventions to support healthy coping processes that can further protect teens against long-term harm from exposure to online risks.

This is the first study to examine situational PTSD symptoms related to four types of adolescent online risk exposure within the week exposure occurred. By applying two competing theoretical frameworks (the adolescent resilience framework and transactional theory of stress), the authors show empirical evidence that suggests short-term coping responses are likely a stress reaction to PTSD, not a protective factor against it.

This paper analyzes the measurement of effective protective rates when there is joint production. It shows that special attention is required when tradables are jointly produced with non‐tradables, and especially when there are significant changes in the prices of non‐tradables. Input‐output formulas for the Balassa and Corden methods are provided.

The prevalence, correlates (child behaviour problems and negative parenting) and determinants (risk and protective factors) of parental need for support were examined in a community sample of 177 mothers with a child aged 1.5‐3.5 years, in order to draw a profile of families that need parenting support. A substantial number of the mothers reported needing support (40% reported need for information, 10% reported family and social support needs). This need was related to child behaviour problems and to negative parenting. Maternal depression, difficult temperament of the child and negative life events, as well as total number of risk factors, significantly predicted the need for support. Satisfaction with support (but not number of support sources) acted as a protective factor.

U.S.S.R. Scale removal at high temperatures. In pickling steels for scale removal, acid solution is now largely used with additions of acid corrosion inhibitors, but this often proves ineffective at temperatures of 50°C. or higher. Some of the literature is surveyed. In the present work the use of the (Russian) ChM as an additive in the pickling baths for different marks of Russian steels is described (the steels are in the U1A class—tabulated analyses). The identity of this material is not disclosed. Figures are tabulated showing time of removal of scale at temperatures of 15 to 70° using 15% sulphuric, and this with either 4 g./1. of ChM or 0.5 g./1. of stannous sulphate. There appears to be little difference: at 15° time is 82 min. for acid alone and 84 to 86 min. for the others; at 70° it is 9 min. for acid alone and 8 min. with additive. Other figures show that the protective action of ChM sharply declines e.g. from 87% at 15° to 12% at 70°; whereas with a metal sulphate there is little change. Further experiments are described and discussed, and it is generally concluded that tin is the most effective inhibitor. A film of this at 70° and over is much more effective than ChM at 35°; the carbon content of the steel is less important; at the higher temperatures there is less risk of damage to steel articles; and it is easier to control time of treatment in pickling bath through practically complete cessation of hydrogen separation when scale removal is finished. Twelve references.—(B. S. Krasikov, etc., Jnl. Appl. Chem., 1957, (7), 993–997.)

GERMANY Nitric acid corrosion of high‐alloy steels. Corrosion diagrams and iso‐corrosion lines of hardenable and non‐hardenable chromium steels, chrome‐nickel steels and some others containing other alloy constituents, in nitric acid solutions up to 67%, have been determined at all temperatures up to their boiling points under atmospheric pressure. The resistance to corrosion of the different types of steel under definite conditions can be derived from the curves constructed from the data obtained. Part of the corrosion data was used to study the effect of different alloy constituents by means of the graphic method. To achieve passivation the minimum content of chromium increases with rising concentration of acid and with increasing content of carbon in the alloy. Excessive additions of chromium have an inhibitive effect also. Manganese is very effective, especially in alloys containing up to 0.7%. Nickel, copper and silicon appreciably increase the risk of attack. Molybdenum has little or no effect except in the 67% boiling acid solutions, where corrosion is reduced as molybdenum content rises to 2%. With higher content the converse happens.

Because many cutting fluids contain hazardous chemical constituents, industries and researchers are looking for alternative methods to reduce the consumption of cutting fluids in machining operations due to growing awareness of ecological and health issues, government strict environmental regulations and economic pressures. Therefore, the purpose of this study is to raise awareness of the minimum quantity lubrication (MQL) technique as a potential substitute for environmental restricted wet (flooded) machining situations.

The methodology adopted for conducting a review in this study includes four sections: establishment of MQL technique and review of MQL machining performance comparison with dry and wet (flooded) environments; analysis of the past literature to examine MQL turning performance under mono nanofluids (M-NF); MQL turning performance evaluation under hybrid nanofluids (H-NF); and MQL milling, drilling and grinding performance assessment under M-NF and H-NF.

From the extensive review, it has been found that MQL results in lower cutting zone temperature, reduction in cutting forces, enhanced tool life and better machined surface quality compared to dry and wet cutting conditions. Also, MQL under H-NF discloses notably improved tribo-performance due to the synergistic effect caused by the physical encapsulation of spherical nanoparticles between the nanosheets of lamellar structured nanoparticles when compared with M-NF. The findings of this study recommend that MQL with nanofluids can replace dry and flood lubrication conditions for superior machining performance.

Machining under the MQL regime provides a dry, clean, healthy and pollution-free working area, thereby resulting the machining of materials green and environmentally friendly.

This paper describes the suitability of MQL for different machining operations using M-NF and H-NF.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2023-0131/