• Title/Summary/Keyword: 김대현

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A Study on the Cutting Optimal Power Requirements of Fast Growing Trees by Circular Saw (원형톱에 의한 속성수 절단 적정 소요동력 산정에 관한 연구)

  • Choi, Yun Sung;Kim, Dae Hyun;Oh, Jae Heun
    • Journal of Korean Society of Forest Science
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    • v.103 no.3
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    • pp.402-407
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    • 2014
  • In this study, Italy poplar(Populus euramericana) was selected for test specimen to measure cutting power when it harvested. The experiment has been controlled as three levels of feed rate (0.41, 1.25 and 2.5 m/s), sawing speed (800, 1,000 and 1,200 rpm), and the five levels of root collar diameter (50, 70, 90 and 110, 130 mm). The harvested volume after 3 years (root collar diameter 50 mm) was 10.5 tons, which falls short of the target amount of biomass is 20~30 ton/ha. In addition, the biomass amount of diameter 90 and 110 mm which reached the target amount were estimated to be 23.5 and 32.5 ton/ha respectively. As a result of experiment, it was found out that power of 128.2 and 175.8 W are consumed in case of cutting with the feed rate of 0.41m/s and minimum sawing speed (800 rpm) respectively. With the working area of 0.3 ha/h, it is considered to present working capacities of 16.5 and 22.8 ton/h respectively. The power consumed at the feed rate of 1.25 m/s is estimated to be 113.8 and 153.7W respectively and working capacity in a working area of 1 ha/h is estimated to be 23.5 and 32.5 ton/h. The power consumed at the feed rate of 2.5 m/s is estimated to be 119.8 and 166.9 W respectively and working capacity in a working area of 2 ha/h is estimated to be 47.0 and 65.5 ton/ha respectively. Therefore, the power source of harvest machine at the feed rate of 1.25, 2.50 m/s and sawing speed of 800 rpm shall be selected as it can process the target amount of estimated biomass.

Productivity and Costs of Felling Operation for Three Harvesting Methods in Mixed Forest Stands (임목수확방법별 벌도작업 생산성 및 비용 분석)

  • Cho, Min-Jae;Choi, Yun-Sung;Mun, Ho-Seoung;Lee, Chung-Geon;Lee, Eun-Jai;Jung, Eung-Jin;Oh, Jae-Heun;Han, Sang-Kyun;Kim, Dae-Hyun;Cha, Du-Song
    • Journal of Korean Society of Forest Science
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    • v.105 no.4
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    • pp.441-448
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    • 2016
  • The purpose of this study was to broaden our knowledge on the productivity and costs of felling operation in three different harvesting methods(whole tree, tree-length and cut-to-length). Felling was conducted in three different harvesting methods with two workers who have different work experiences. Worker A and B have had felling experiences for about 5 years and 15 years, respectively. Felling productivity in whole tree method was $10.3m^3/SMH$ for worker A and $12.7m^3/SMH$ for worker B. Felling costs for worker A and B were $2,066won/m^3$ and $2,201won/m^3$, respectively. Although felling productivity of worker B in whole tree method was higher than worker A, felling costs of worker A were similar to worker B because the wage of worker B was more expensive than the wage of worker A (p>0.05). In tree-length method, felling cost of worker B were cheaper than that of worker A. Felling productivity and cost in tree-length method were $2.2m^3/SMH$ and $9,890won/m^3$ for worker A and $3.3m^3/SMH$ and $8,459won/m^3$ for worker B, respectively (p<0.05). In cut-to-length method, felling productivity and cost were $2.3m^3/SMH$ and $9,584won/m^3$ for worker A and $3.0m^3/SMH$ and $9,395won/m^3$ for worker B, respectively. Felling productivity of worker B was higher than that of worker A(p>0.05). Our preliminary results found that harvesting methods and worker's experiences highly affect on the productivity and costs of felling operations. These results should be useful for forest managers when planning cost-effective harvesting operations.

Ultrastructrual Change of Myocardium in Open Cardiac Surgery with Cold Blood Cardioplegia (개심술 시 냉혈성 심정지액 사용에 따른 허혈 전후 심근 미세구조의 변화)

  • 김병호;김대현;공준혁;조준용;손윤경;이종태
    • Journal of Chest Surgery
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    • v.36 no.9
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    • pp.638-645
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    • 2003
  • The purposes of this study were to evaluate the effect of myocardial protection with our cold blood cardioplegic solution and to observe the relationship between ultrastructural study and other evaluation methods and its effectiveness. Material and Method: We evaluated the changes of myocardial ultrastructure using semi-quantitative scoring system, CK-MB fraction, SGOT and LDH1/LDH2, and EKG in 18 patients undergoing valvular heart surgery and coronary artery bypass grafting (CABG). Right atrial auricular biopsies were taken before the cardiopulmonary bypass (CPB) and shortly after the end of CPB. Myocardium-related serum enzymes & EKG were checked for 3 days of postoperative period and their postoperative peak enzyme value and observed new Q wave & ST segment elevation in EKG were choosen. Result: There were 8 males and 10 females, and their mean age was 55.6$\pm$13. Eight patients underwent valvular heart surgery and ten coronary artery bypass grafting, The mean CPB time was 119$\pm$29 minutes and the mean aortic cross-clamp (ACC) time was 75.4$\pm$24 minutes. Before the start of CPB, the mean mitochondrial score was 4.28$\pm$0.53 and after the end of CPB, it significantly increased to 2.35$\pm$0.79. There was no evidence of perioperative myocardial infarction in terms of myocardiumrelated serum enzyme value and Q wave and ST change in EKG. There was no significant relationship between pre-CPB and post-CPB mitochondrial score and the mean time of CPB and ACC, and the mean value of postoperative peak CK-MB, SGOT and LDH1/LDH2, but there was relatively positive correlation of CPB time with peak LDH1/LDH2. Conclusion: Despite the apparent satisfactory results in myocardium-related serum enzymes & EKG, with this study using the cold blood cardioplegic solution, there were many changes in myocardial ultrastructures, and more studies are needed to obtain further information.

Post Feeding Trypsin Activity in the Digestive Organs and the Gastric Evacuation Rate of Litopenaeus vannamei (Boone) (먹이섭취 후 흰다리새우, Litopenaeus vannamei (Boone) 소화기관의 trypsin 활성 및 배설률)

  • Kim, Su-Kyoung;Kim, Dae-Hyun;Kim, Bong-Rae;Kim, Jong-Seek;Cho, Yeong-Rok;Seo, Hyung-Cheol;Kim, Jong-Hwa;Han, Chang-Hee;Jang, In-Kwon
    • Journal of Aquaculture
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    • v.19 no.1
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    • pp.1-6
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    • 2006
  • The tryptic enzyme activities from hepatopancreas, foregut, midgut and feces were examined to optimize the feeding method in whiteleg shrimp, Litopenaeus vannamei. The highest tryptic enzyme activity was found in hepatopancreas. The enzyme activities of hepatopancreas were 4 times higher than those of foregut per mg dry weight at 30 minutes feeding. Post feeding period, the activities of hepatopancreas increased continuously up to 30 hours after feeding. Trypsin activities of foregut showed about 3 times higher than did those of midgut. Average activity of foregut reached the pick with $303{\pm}68\;(mean{\pm}SE)$ nmol/mg/min at two hours after feeding and kept the activity up to 4 hours after feeding and thereafter the activity decreased. Average tryptic enzyme activity of midgut increased to $96{\pm}26nmol/mg/min$ up to two hours after feeding and it decreased to $52{\pm}17nmol/mg/min$ at five hours after feeding eventhough the gastric evacuation rate was still 50% by then. Foregut clearance occurred in 30 minutes after feeding and midgut weight increased up to 2 hours after feeding. Also we found that the maximal food ingestion in foregut was equivalent to the average 0.3% of its body weight by 30 minutes after feeding. Up to 5 hours after feeding, the weight ratio of midgut to body weight reduced, but still the weight ratio of foregut to body weight kept the similarity until then. These indicated that the tryptic enzyme activity and the clearance rate are different among the digestive organs and between forgot and midgut during the post feeding period in whiteleg shrimp.

A Study of Home Care Needs of Patients at Discharge and Effects of Home Care -Centered on Patients Discharged from a Rural General Hospilal- (퇴원환자의 가정간호요구와 가정간호사업의 효과 분석 - 일 종합병원을 중심으로)

  • Choi, Yun Soon;Kim, Dai Hyun;Storey, Margaret;Kim, Cho Ja;Kang, Kyu Sook
    • The Korean Nurse
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    • v.31 no.4
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    • pp.77-99
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    • 1992
  • The study was carried out at W. hospital, an affiliated hospital of Y university, involved a total of 163 patients who were discharged from the hospital between May 1990 und March 199J. Data collection was twice, just prior to discharge and a minimum of three months post discharge. Thirty patients who lived within a hour travel time of the hospital received home care during the three months post discharge. Nursing diagnoses and nursing interventions For these patients were analyzed in this study. The results of the study are summarized as follows : 1. Discharge needs for the subjects of the study were analyzed using Gordon's eleven Functional categories and it was found that 48.3% of the total sample had identified nursing needs. Of these, the needs most frequently identified were in the categories of sexuality, 79.3 %, health perception, 68.2 % self concept, 62.5 %, and sleep and rest 62.5 %. Looking ut j he nursing diagnosis that were made for the 30 patients receiving home care, the following diagnoses were the most frequently given; alteration in sexual pattern 79.3%, alterations in health maintenance, 72.6%, alteration in comfort, 68.0%, depression, 64.0%, noncompliance with diet therapy, 6.3.7%, alteration in self concept, 55.6%, and alteration in sleep pattern, 53%. 2. In looking at the effects of home nursing care as demonstrated by changes in the functional categories over the three month period, it was Found that of the 11 functional categories, the need level for health perception, nutrition, activity and self concept decreased slightly over the three month period. On the average sleep patterns improved, but restfulness was slightly less and bowel elimination patterns improved but satisfaction with urinary elimination was slightly less. On the other hand, role enactment, sexuality, stress management and spirituality decreased slightly. The only results that were statistically significant at the 0.05 level were improvement. in digestion and decrease in pain. No statistically significant changes were found in ability related to ADL, the total ADL Score at discharge was $19.78{\pm}8.234, and after 3 months $19.01{\pm}8.12$. Considering that a majority of the patients were over 60 years of age and that many had brain or spinal cord injuries, the fact that their ADL ability did nor deteriorate after discharge can be interpreted as related to a positive impact by the home health care nurses. Similarly there was a slight be not statistically significant decrease in the quality of life scores between the two lest times(l47.83 at discharge and 113.02 at the three month period). Again, when the chronic nature of thee problems facing these patients is considered this maintenance of quality of life can be interpreted as a positive impact by the home health care nurses. 3. One of the home care nursing activities was diagnosis. For this activity it was found that for nine functional health categories(sexuality and spirituality excepted) there were 20 nursing diagnoses. The most frequent were noncompliance, alteration in skin integrity both actual and potential, and impaired physical mobility in that order. 4. Delivery of home health care by the home health nurses included the following nursing activities; assessment, patient education, demonstration of care activities, counselling, direct care to the patient and referrals. Direct care included changing dressings, bladder irrigations, changing Foley catheters, measurement of residual urine, perineal care, position change, back care, oral hygiene, exercise and massage of motion exercises, cleansing enemas, tracheostomy suctioning and tracheostomy care, care of dentures, applications of heat and other similar nursing activities. In conclusion almost 50% of (he sample indicated a need for continued nursing care at the time of discharge and for the patients in the sample who received home care there was a slight decrease in nursing needs but while the patients had chronic and debilitation problems there was ill decrease in ADL abilities or in quality of life. Further study needs Lo be done La increase the reliability and validity of the tool that was used to measure home health care needs. It is also recommended that study by done using a randomized sampling with a control group to compare patients who receive home care with those who do not.

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The Early Results of Tricuspid Valvuloplasty with Using the Edwards MC3 Annuloplasty System (Edwards MC3 Annuloplasty System을 이용한 삼첨판 성형술의 조기 성적)

  • Oh, Tak-hyuck;Cho, Joon-Yong;Lee, Jong-Tae;Kim, Gun-Jik;Kim, Dae-Hyun
    • Journal of Chest Surgery
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    • v.42 no.1
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    • pp.28-33
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    • 2009
  • Background: Functional tricuspid regurgitation (TR) greater than or equal to a mild grade requires tricuspid valvuloplasty, and tricuspid valvuloplasty with ring annuloplasty has shown good outcomes. We report here on our early experience with the Edwards $MC^3$ annuloplasty system (Edwards LifeSciences, Irvine, CA). Material and Method: From November 2004 to July 2006, 72 patients with tricuspid annular dilatation and TR underwent tricuspid valvuloplasty with using the Edwards $MC^3$ annuloplasty ring. Sixty-eight patients were operated on via median sternotomy and four patients were operated on using robotic assisted minimal invasive thoracotomy. The patient population included 21 males and 51 females and their mean age was $53.9{\pm}12.3$. The mean grade of TR, as assessed by the preoperative echocardiography, was $2.2{\pm}1.0$. The mean NYHA functional class was $3.1{\pm}0.8$. The mean left ventricular ejection fraction was $57.0{\pm}9.9$%. Result: The TR and NYHA functional class, as assessed by postoperative echocardiography, was significantly reduced (mean=$0.4{\pm}0.6$ and $2.0{\pm}0.7$, respectively p<0.001). There was one case of hospital mortality. One patient required permanent pacemaker insertion for third degree atrioventricular block. Conclusion: Our study shows that the Edwards $MC^3$ remodeling ring is easy to implant and it effectively corrects functional TR with excellent clinical and echocardiographic outcomes. Further follow-up and a larger clinical series are required to establish the long-term stability of this repair technique.

Combination of Natural Products Removing ROS for Growth Promoting Effects of the Useful Enterobacteria Lacobacillus sp. (ROS 제거기능을 갖는 천연산물로부터 장내 유용세균 Lacobacillus속의 성장을 촉진시키는 조합의 구성)

  • 김종덕;김민용;서효진;김봉조;김대현;김은옥;정해영;공재열
    • Microbiology and Biotechnology Letters
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    • v.30 no.3
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    • pp.270-281
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    • 2002
  • The growth of Enterobacteria, Lactobacillus acidophilus and L. plantarum was promoted by natural products themselves bearing antioxidative capacity and combined two, three and four kinds of them.1. acidophilus was promoted by Paeonia japonica, Acori graminei rhizoma, Aurantii nobilis pericarpium, alone, and two mixed combinations were composed of Acori graminei rhizoma and Cinnamomi cortex, Aurantii nobilis pericarpium and Puerariae radix, and three mixed combinations were formed with Cimicifugae rhi- zoma, Cinnamomi cortex and Glycyrrhizae radix, and four mixed combinations were made up Glycyrrhizae radix, Theae folium, Scutellaria baicalensis george and Cinnamomi cortex. There four combination promoted growth of 1. acidophilus with 1.3 times than that of control, and their antioxidative capacity also higher than that off times, the ratio of elimination of hydroxyl radical was more than 70% in dilution rate of 100 times. In the case of 1. plantarum was premoted by Corm fructus, Nelumbo nuclfera gaertner Sophorae flos, alone, and two mixed combinations were organized with Schizandrae Iructus and Theae folium, Paeonia japonica and Epimedii herba, and three mixed combinations were combined with Corni fructus and Theae folium and Paeonia japonica, Corni fructus and Coptidis rhizoma and Schieandrae fructus, and four mixed combinations were composed of Corm fructus, Theae folium, Coptidis rhizoma, Scutellaria baicalensis george, and Corm fructus, Schizandrae fructus, Paeonia japonica, Theae folium. These four combinations assisted growth of 1. plantarum with 1.5 times than that of control, and their antioxidative capacity also higher than that of 4-5 times, the ratio of elimination of hydroxyl radical was more than 75% in dilution rate of 100 times. As these combinations of natural products could activate some parts of body, they might be applied pharmaceuitcal sources, functional foods, and expected to fermentative beverages.

Visual fatigue in Watching 3 Dimension Television (3D TV 시청에 있어서 시청 피로)

  • Yoon, Jeong Ho;Lee, Ikhan;Kim, Taehyun;Kim, Jae-Do
    • Journal of Korean Ophthalmic Optics Society
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    • v.17 no.1
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    • pp.47-52
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    • 2012
  • Purpose: This study was to evaluate visual fatigue with passing of watching 3D TV in short term and with experience of watching 3DTV in long term. Methods: 98 adult subjects aged $33.5{\pm}5.5$ years (22 to 51 years; 12 females and 86 males) agreed to participate in this study. Subjects were asked to watch 52 inch LED 2D and 3D television (Shutter glasses method) at 2.7 meters for 65minutes with wearing their habitual glasses or contact lenses. For evaluating visual fatigue, subjects were verbally responded to 11 questions : eye straining, eye paining, dry eye, sore eye, watery eye, photophobia, blur vision, diplopia, eye fatigue, headache, and dizziness with scale 0 to 3 at each measurement while watching 3D and 2D TV. Results: The mean scores of visual fatigue were $2.08{\pm}2.14$, $3.19{\pm}3.02$, $3.40{\pm}3.37$, $3.53{\pm}3.07 $for after 5 minutes, 25 minutes, 45 minutes, and 65 minutes respectively for 3D TV, and $0.40{\pm}1.03$, $0.22{\pm}0.70$, $0.22{\pm}0.58$, and $0.17{\pm}0.52$ after 25, 45, and 65 minutes respectively for 2D TV. Visual fatigue for watching 3D TV was significantly higher than for watching 2D TV at all measurements sessions (paired t-test, p < 0.001). The visual fatigue significantly increased during watching 3D TV for 65 minutes (p < 0.001, RM-ANOVA). The visual fatigue during watching 3D TV was significantly increased until 25 minutes (paired t-test, p < 0.001), stable after that. For correlation between visual fatigue and 3D watching experience, the more 3D watching experiences were significantly the less visual fatigues in photophobia, blur vision, diplopic and dizzy symptoms (ANOVA, all F(1, 96) = 4.500, all p < 0.05), but there was not significantly different in the other symptoms (ANOVA, F (1, 96) = 2.123, p = 0.148). Conclusions: Visual fatigue for watching 3D TV was higher than for watching 2D TV, increase by 25 minutes. It was different by symptoms for correlation between visual fatigue and 3D watching experience.

Effect of 1-methylcyclopropene and ethylene-absorbent treatments on quality changes of Prunus mume fruit during storage (1-MCP 처리 및 에틸렌 흡착제가 '백가하' 매실 저장에 미치는 영향)

  • Kim, Dae-Hyun;Bae, Jung Mi;Park, Jin Ju;Choi, Jeong Hee;Ku, Kyung Hyung;Lim, Jeong-Ho
    • Food Science and Preservation
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    • v.23 no.4
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    • pp.479-487
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    • 2016
  • This study was conducted to investigate the effect of 1-methylcyclopropene (1-MCP) and ethylene-absorbent on the qualities of Prunus mume fruit. Prunus mume fruits were stored without film packaging (Cont), packed in LDPE film (Cont-P), and packed with ethylene-absorbent (Cont-PE). Fruits were treated with 1-MCP (1 ppm) for 24 hr at $1^{\circ}C$. After treatment, fruits were packed in LDPE film (MCP-P) and with ethylene-absorbent (MCP-PE) and then stored at $1^{\circ}C$ for 8 weeks. Total soluble solids increased during storage but decreased after 6 weeks while total acidity decreased during storage. Cont was almost completely decayed after 8 weeks of storage while Cont-P, Cont-PE, MCP-PE, and MCP-P were 46, 69, 83, and 5% decayed, respectively. L value decreased but a value increased during storage in all samples. Firmness of peel and flesh of samples decreased gradually for 8 weeks. Respiration rate did not show any significant difference among samples. Ethylene production of Cont showed $0.05{\mu}L/kg/h$ but immediately after 1-MCP treatment, it showed $0.02{\mu}L/kg/h$. Oxalic and malic acids decreased while citric acid increased during storage; fructose and glucose substantially decreased after 8 weeks whereas sorbitol and sucrose increased upto 4 weeks and then decreased thereafter. Based on these results, packing the fruits treated with 1-MCP could extend the freshness of Prunus mume fruit.

Determination of the shelf life of cricket powder and effects of storage on its quality characteristics (식품원료용 귀뚜라미 분말의 저장 중 품질특성 및 유통기한 설정)

  • Kim, Dae-Hyun;Kim, Eun-Mi;Chang, Yoon-Je;Ahn, Mi-Young;Lee, Yong-Hwan;Park, Jin Ju;Lim, Jeong-Ho
    • Food Science and Preservation
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    • v.23 no.2
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    • pp.211-217
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    • 2016
  • This study was carried out to determine the shelf-life of cricket powder and investigate the changes in its quality during storage. To determine the shelf-life, cricket powder was stored at temperatures of 25, 35, and $40^{\circ}C$ for 6 months. The changes in quality parameters of the cricket powder, such as moisture content, color, acid value, volatile base nitrogen (VBN), fatty acid, growth of microorganisms, and sensory appeal were investigated. The moisture content of the cricket powder increased during storage but did not show any significant difference at 6 months of storage. L value was increased at $25^{\circ}C$ storage but decreased at 35 and $40^{\circ}C$. However, there were no significant different in a and b values. The acid value decreased more rapidly at higher temperatures, while the VBN content was not changed. The major composition of fatty acids of cricket powder were palmitic acid, oleic acid, and linoleic acid. Their content was not changed at various the storage temperatures. No aerobic and coliform bacteria grew in the powder during the whole storage period. Cricket powder stored at $25^{\circ}C$ and $35^{\circ}C$ showed similar scores in sensory evaluation, but it storaged at $40^{\circ}C$ showed the significant difference (p<0.05). Moisture content, acid value, oleic acid, and flavor were selected as the criteria for shelf-life establishment of cricket powder. Based on these parameters, especially the moisture content, the shelf life of cricket powder was likely to be 18 months when stored at $25^{\circ}C$.