Maximizing the Recycling of Iron Ore Pellets Fines Using Innovative Organic Binders

This research work focuses on the practicality of using organic binders for the briquetting of pellet fines. The developed briquettes were evaluated in terms of mechanical strength and reduction behavior with hydrogen. A hydraulic compression testing machine and thermogravimetric analysis were incorporated into this work to investigate the mechanical strength and reduction behavior of the produced briquettes. Six organic binders, namely Kempel, lignin, starch, lignosulfonate, Alcotac CB6, and Alcotac FE14, in addition to sodium silicate, were tested for the briquetting of pellet fines. The highest mechanical strength was achieved using sodium silicate, Kempel, CB6, and lignosulfonate. The best combination of binder to attain the required mechanical strength even after 100% reduction was found to be a combination of 1.5 wt.% of organic binder (either CB6 or Kempel) with 0.5 wt.% of inorganic binder (sodium silicate). Upscaling using an extruder gave propitious results in the reduction behavior, as the produced briquettes were highly porous and attained pre-requisite mechanical strength.

How Can Flowers and Their Colors Promote Individuals' Physiological and Psychological States during the COVID-19 Lockdown?

The global spread of COVID-19 has disrupted the normality of people’s daily lives, leading the population to social distancing and isolation. The closure of green areas also affected the well-being of the individual during the COVID-19 pandemic. Viewing flowers is expected to have similar positive effects to viewing natural scenery. Therefore, this study investigates how white, red, and yellow flower colors affect individuals’ psychological and physiological well-being. The experiment was conducted in an office-like setting with 50 participants. Participants looked at each flower color for 3 min. Electroencephalograms (EEGs), heart rate variability, and skin conductivity were measured to evaluate physiological responses along with both the semantic differential questionnaire (SD) and the Profile of Mood States (POMS) to assess psychological responses. EEGs showed that the mean values of alpha relative power in the prefrontal lobe were significantly higher when viewing yellow and red flowers vs. white flowers. Furthermore, heart rate variability revealed that viewing yellow and red flowers increased parasympathetic nerve activity significantly. After viewing the yellow and red flowers, the average results for each subscale of the POMS questionnaire improved. The vigor (V) subscale and overall mood status values were significantly improved. The results of the SD method revealed that viewing yellow and red flowers resulted in a significantly higher sense of relaxation, cheerfulness, and comfort than viewing white flowers.

Benefits of Indirect Contact With Nature on the Physiopsychological Well-Being of Elderly People

OBJECTIVES

Exposure to nature or to green space has positive mental health benefits. Closing of parks and green spaces during the COVID-19 pandemic has reduced options for mental health and well-being benefits and could have a greater impact on vulnerable populations, especially the elderly. The present study, therefore, explores the physiopsychological impacts of indirect contact with nature, using forest imagery, on the brain activity and autonomic nervous systems of elderly people.

STUDY DESIGN

A within-subject design experiment was used.

METHODS

Thirty-four participants aged 82.9 ± 0.78 years were asked to look at bamboo and urban images for 2 min. During the visual stimulation, α relative waves were measured using electroencephalography as an indicator of brain activity. Heart rate variability and skin conductance (SC) responses were utilized as indicators of arousal. Afterward, psychological responses were evaluated using the semantic differential and the Profile of Mood States questionnaires.

RESULTS

Visual stimulation with bamboo image induced a significant increase in α relative waves and parasympathetic nervous activity and a significant decrease in SC. In addition, a significant increase in perceptions of "comfortable," "relaxed," "cheerful," and "vigorous" feelings was observed.

CONCLUSIONS

Indirect contact with nature enhances the physiological and psychological conditions of the elderly. Findings can be used to guide the new design, renewal, and modification of the living environments of the elderly and those who are unable to get outside.

Foliage colors improve relaxation and emotional status of university students from different countries

The therapeutic advantages of seeing plants have gained increasing consideration in stressful modern societies, however, evidence-based studies on how physiological and emotional states of individuals from different nationalities change when seeing different foliage colors are limited. The study was conducted to explore the physiological and psychological advantages of foliage colors as visual stimuli. The experiment included 40 men from two nations (age: 21.34 ± 3.50 years) and was carried out using five foliage colors including green, light green, green-yellow, green-red and green-white. Participants were exposed to each color for 2 min, when seeing the foliage colors, eye movements and oxy-Hb concentrations were continuously measured. Subjective evaluations of emotions were performed utilizing a semantic differential questionnaire. A significant decrease in oxy-Hb concentration in the frontal lobe was associated with the viewing of green and green-white plants by the Japanese participants and with viewing light green and green-yellow by the Egyptian participants. Participants spent higher fixation numbers and longer durations on these colors. The findings indicate that viewing of these plant colors was positively associated with physiological relaxation. Furthermore, these colors were associated with more positive feelings, such as calmness, comfort and naturalness. Therefore, the presence of these colors in spaces may have positive impacts on relaxation and emotional status.

Laparoscopic versus open appendectomy: a prospective comparative study of 227 patients

BACKGROUND

Although laparoscopic appendectomy is widely practiced in developed countries, still there are many questions regarding the advantages and disadvantages of this approach in the treatment of acute appendicitis. Several controlled trials have been conducted, some in favor of laparoscopic appendectomy others not. The aim of this study was to evaluate laparoscopic appendectomy in comparison with open appendectomy, with special emphasis on postoperative septic complications.

METHODS

For this study, 227 consecutive patients (159 males and 68 females) with a diagnosis of suspected appendicitis between 1995 and 1999 were assigned either to laparoscopic appendectomy (n = 108) or open appendectomy (n = 119). The patients were assigned according to insurance company approval and patient preference. There were no exclusion criteria and no age limits in this study.

RESULTS

Wound infection was significantly higher in the open group (incidence, 7.6%) than in the laparoscopic group (incidence, 0%; p <0.003). Intraabdominal infections were equal in both groups. Hospital stay was significantly shorter in the laparoscopic group (p <0.046), but operative time was little longer than in the open group (p <0.002). Conversion to open surgery was necessary in one case.

CONCLUSIONS

Laparoscopic appendectomy is as safe and effective as the open procedure. It significantly reduces the rate of postoperative wound infection. However, it is still acceptable to perform the open procedure, especially in hospitals without a large amount of laparoscopic experience.