Polyvinyl Chloride Containers Research Articles

Plastic film mulching maintains soil organic carbon by increasing fungal necromass carbon under manure application

AbstractMicrobial necromass carbon (MNC) is a major contributor to soil organic carbon (SOC) sequestration. Fertilization combined with plastic film mulching, as an intensive agricultural practice to increase crop yields, affects soil microbial growth and metabolism. Nevertheless, how fertilization combined with mulching affects SOC sequestration by mediating MNC dynamics remains elusive. Here, the mulching and no‐mulching sub‐treatments were set under three fertilization treatments (no fertilization, NF; inorganic fertilization, IF; manure, MF), and a 900‐day field incubation experiment using polyvinyl chloride containers was conducted in the buffer zone of NF treatment. We investigated the effects of fertilization combined with mulching on MNC composition (including fungal necromass carbon, FNC; and bacterial necromass carbon, BNC) and qualified their contributions to SOC sequestration. The MF treatment with/without mulching significantly increased the contents of MNC, FNC, BNC, and SOC by 97%–122%, 81%–94%, 152%–210%, and 60%–70% compared with the NF treatment without mulching over 900 days, respectively. The MNC content had a strongly positive correlation with particulate organic carbon and microbial biomass C (p < 0.01). During the incubation stage, the proportion of MNC in SOC was higher in the IF (37%–42%) and MF (40%–44%) treatments with/without mulching than that in the NF treatment with/without mulching (31%–35%). On day 900, mulching significantly decreased the MNC content by 8.7% and 7.8%, and decreased the proportion of MNC in SOC by 5.1% and 5.8% under the NF and IF treatments, respectively. In contrast, mulching did not significantly affect the MNC and SOC contents, but significantly increased the FNC content by 4.8% under the MF treatment on day 900. Mulching significantly decreased the proportion of BNC in SOC regardless of fertilization, and increased the proportion of FNC in SOC under the MF treatment on day 900. Overall, our findings suggest that mulching under manure application maintains SOC sequestration by promoting FNC retention.

Thermal and energy performance evaluation of a dry floor heating system based on hybrid heat storage aggregates for field application

The application of thermal energy storage (TES) systems in buildings has increased with growing interest in renewable energy technology. TES systems that use phase change materials (PCMs) are preferred over other energy storage methods. This study produced an activated carbon (AC)-based shape-stabilized PCM (ACS-PCM) using AC and n-eicosane, which was injected into a polyvinyl chloride (PVC) container to manufacture a heat storage container. The thermal properties of the ACS-PCM were analyzed to evaluate its performance when the manufactured heat storage container was applied to a dry floor heating system. Because of its high thermal conductivity, the ACS-PCM was superior to n-eicosane in heat transfer when heated. Moreover, the ACS-PCM exhibited a time-lag effect owing to heat storage during heating and free cooling. The PCM dry floor heating system consumed 77.3 % of the energy of the wet floor heating system. Finally, to increase the heat transfer efficiency, the ACS-PCM and pure n-eicosane were simultaneously injected into the PCM container to fill the gap between them; however, there was a temperature difference, highlighting the need for improved thermal conductivity of PCM container materials.

Heating efficiency enhanced by combination of phase change materials and activated carbon for dry floor heating system

Phase change materials (PCMs) have diverse applications in energy storage, buildings, cooling, and heat exchangers. In this study, n-docosane and activated carbon (AC) were combined using the vacuum impregnation method to form an aggregate, which was then injected into a Poly vinyl chloride container and applied to a dry floor heating system. Thermal storage, gravimetric, conductivity, and specific heat analyses were performed to evaluate the thermal performance of n-docosane and AC-based heat-storage aggregate (D-HSA). The dynamic heat transfer performance and power consumption of the dry floor heating system after D-HSA application were then evaluated. Pure n-docosane and D-HSA showed latent heat capacities of 242.7 J/g and 235.1 J/g and 92.10 J/g and 92.66 J/g during heating and cooling. In terms of thermal durability, D-HSA was more stable than pure n-docosane. Thermal conductivity analysis revealed that D-HSA had a high thermal conductivity (approximately 597 %) in the liquid state. In the field-based dynamic heat transfer analysis experiment, the PCM dry floor heating system filled with D-HSA had the advantages of both dry and wet floor heating systems, namely, a fast surface temperature increase rate and the time-lag effect, respectively. Therefore, the PCM dry floor heating system can compensate for the disadvantages of the dry and wet floor heating systems and can be considered an efficient heating system in terms of energy savings.

Extended stability of vasopressin 0.2 unit/mL in PVC containers.

Vasopressin is used to maintain blood pressure in vasodilatory shock. Vasopressin is diluted from concentrated vials prior to administration as a continuous infusion. This study evaluates the physical and chemical stability changes of vasopressin diluted to 0.2 units/mL with 0.9% sodium chloride injection in polyvinyl chloride (PVC) bags stored under refrigeration. Vasopressin Injection, USP, 20 unit/mL solution was diluted to 0.2 unit/mL with 0.9% sodium chloride injection, and stability changes were evaluated over 10 days via mass spectrometry on days 0, 7, and 10. Solutions of vasopressin 0.2 unit/mL in 0.9% sodium chloride injection in PVC bags were physically stable and showed less than 10% degradation over 10 days of refrigerated storage. Vasopressin 0.2 unit/mL may be given a beyond-use date (BUD) of 10 days based on United States Pharmacopeia BUD recommendations, with this study showing less than 10% degradation over 10 days of refrigerated storage.

MP32-09 PATIENT CONTROLLED URETHRAL HYDRODISTENTION REDUCES PAIN DURING MALE FLEXIBLE CYSTOSCOPY

You have accessJournal of UrologyCME1 May 2022MP32-09 PATIENT CONTROLLED URETHRAL HYDRODISTENTION REDUCES PAIN DURING MALE FLEXIBLE CYSTOSCOPY Daniel Wagner, and William Lin Daniel WagnerDaniel Wagner More articles by this author , and William LinWilliam Lin More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002581.09AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Flexible cystoscopy is typically performed under local anesthesia with intraurethral insertion of aqueous lidocaine gel. Male patients often experience significant discomfort as the cystoscope is negotiated past the membranous and prostatic urethra. The objective of this study is to determine whether patient controlled urethral hydrodistention can reduce patient discomfort during male flexible cystoscopy. METHODS: Flexible cystoscopy was performed using Karl Storz 15 F flexible cystoscope by a single urologist in cystoscopy naive male patients, with or without patient controlled urethral hydrodistention. 10 cc of 2% aqueous lidocaine gel was introduced into the urethra and left in place for 10 minutes prior to initiation of the procedure. Urethral hydrodistention was achieved by having the patients forcibly compress 250 ml flexible polyvinyl chloride container of sterile sale as the flexible cystoscope was negotiated past the urethra. clinical outcomes were assessed using analog pain scale post procedure to assess pain associated with the procedure. RESULTS: A total of 63 cystoscopy naive men underwent flexible cystoscopy. 32 patients were in the urethral hydrodistention group with median age of 47. 31 patients were in the control group with median age of 50. Analog pain score was 1.96 in the urethral hydrodistention group and 5.68 in the control group (p <0.01). CONCLUSIONS: In our study, patient controlled urethral hydrodistention significantly reduces pain associated with flexible cystoscopy in cystoscopy naive male patients. It is reasonable to incorporate this technique as part of the male flexible cystoscopy procedure. Source of Funding: None © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e535 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Daniel Wagner More articles by this author William Lin More articles by this author Expand All Advertisement PDF DownloadLoading ...

Functional and Pasting Properties of Gari Produced from White-fleshed Cassava Roots as Affected by Packaging Materials and Storage Periods, and Sensory Attributes of the Cooked Gari Dough (eba)

Gari (roasted fermented cassava grits) is the most popular product consumed in West Africa and an important food product in the diet of millions of people in developing countries. The study investigated the effect of packaging materials (PM) and storage periods on the functional and pasting properties of Gari produced from white-fleshed cassava roots and sensory attributes of the cooked Gari dough (eba). Gari was produced using the standard method and packaged in a polypropylene woven sack (PP) and polyvinyl chloride container (PVC). Gari was stored for 24 weeks at room temperature and sampled at four-week intervals for functional and pasting properties, and sensory evaluation of the eba, using standard methods. The results showed that the storage periods significantly affected all the functional (except swelling power) and pasting properties of the Gari, and PM had no significant (p&gt;0.05) effect on the functional (except bulk density) and pasting properties. Also, the PM had no significant effect on the sensory attributes of the eba except for the mouldability (p&lt;0.05). The setback viscosity of the Gari packaged in PVC had a significant (p&lt;0.05, r= -0.58) negative correlation with the texture of the eba. The panellists preferred all the sensory attributes of the eba made from the Gari stored in PP compared to that made from Gari stored in PVC. Therefore, packaging Gari in PP may keep most of the properties preferred by consumers when stored for up to 5 months.

A simple microanalytical method for trace elemental determination in plutonium samples using energy dispersive X-ray fluorescence

A simple microanalytical method for trace elemental determinations in plutonium (Pu) solution samples was developed using Energy Dispersive X- Ray Fluorescence (EDXRF) spectrometry. A very small sample volume (200 μL) of Pu solution was taken for analysis and the major matrix Pu was separated using the extractant, Tri n-Butyl Phosphate (TBP), in 4 M HNO3 medium. Aliquot of 5 μL of the aqueous phase containing only the trace elements were deposited on a thin transparent mylar film inside the PVC (Poly Vinyl Chloride) EDXRF sample container and dried in ambient atmosphere inside a radioactive fume hood. After drying, the container was sealed with PVC lids. Two pure Pu solutions spiked with different trace elements having concentration of 6.25 and 23.25 μg/mL, were analyzed with RSD (Relative Standard Deviation) of 6.6 and 4.2% (1 σ, n = 3), and the average deviation from the expected values calculated on the basis of sample preparation were 8.9 and 6.6%, respectively. The developed methodology requires small amount of sample, extractant, and therefore generates less radioanalytical waste. Moreover, due to the requirement of small amount of sample, sealed inside a PVC container, the measurements could be carried out in ambient atmosphere without putting the instrument inside glove box. Further, the simple instrumentation of EDXRF, made this methodology very much ideal for the routine analysis of plutonium based samples.

Effect of Packaging Materials and Storage Conditions on the Degradation of Xanthophylls in Yellow-Maize Ogi Powder

The need to evaluate the effects of packaging materials and storage conditions on the degradation of xanthophylls in yellow maize ogi powder is important due to its health implication. Ogi powder was packaged in high-density polyethylene bag (HDPE), polypropylene woven sack (PP), and polyvinyl chloride container (PVC). The samples were stored under different conditions for 12 weeks and sampled at three-week intervals for analysis using High Performance Liquid Chromatography. The result showed that the total xanthophyll content of the ogi powder was 10.39 µg/g before storage with of zeaxanthin having the highest value (6.73 µg/g) and lutein (3.66 µg/g) the least. The reduction in lutein and zeaxanthin contents was significant in the ogi powder packaged in HDPE stored at 35°C and 50% relative humidity (RH). Therefore, PVC is recommended at 34°C and RH of 54% for up to 6 weeks while HDPE may be used at 28°C and 68% RH for 9 weeks, and that of PP might be 35°C and 50% RH if the storage period is extended to 12 weeks.

Retention of Pro-vitamin A Carotenoids in Ogi Powder as Affected by Packaging Materials and Storage Conditions

The effect of different packages and storage conditions on the retention of pro-vitamin A carotenoids (pVAC) in ogi powder produced from yellow-seeded maize was investigated to study its storage stability on micronutrient retention. The ogi powder produced was packaged in a high-density polyethylene bag (HDPE), a polypropylene woven sack (PP), and a polyvinyl chloride container (PVC), and stored in different conditions for 12 weeks with sampling done at three-week intervals for pVACanalysis. At the end of the storage period, ogi powder packaged in HDPE stored outside the storage box had the highest percentage retention (31.32%) of trans-β-carotene and that packaged in PVC container stored in the lighted compartment had the least (21.57%). Therefore, HDPE could be a good package for the retention of trans-β-carotene (which is the most bioactive) in ogi powder when stored at a temperature of 27°C and relative humidity of 73%.

Stability of penicillin G sodium diluted with 0.9% sodium chloride injection or 5% dextrose injection and stored in polyvinyl chloride bag containers and elastomeric pump containers

The stability of penicillin G sodium solutions stored in polyvinyl chloride (PVC) bags or elastomeric pump containers was studied. Test samples were prepared by diluting powdered penicillin G sodium (10 million units/10-mL vial) to solutions of 2,500 or 50,000 units/mL with 0.9% sodium chloride injection or 5% dextrose injection. The preparations were transferred to 250-mL PVC bags and elastomeric pump containers. All samples were prepared in triplicate and stored at 5°C. Chemical stability was measured by a stability-indicating high-performance liquid chromatographic (HPLC) assay and by pH evaluation. Particulate matter was evaluated according to compendial standards using a light-obscuration particle count test. Preparations were visually examined throughout the study. After 21 days of storage, all test samples remained chemically stable, with an HPLC assay recovery value of more than 90% of the initial value. After 28 days, all samples prepared with either diluent and stored in PVC bags, as well as the samples diluted to 2,500 units/mL with sodium chloride injection and stored in elastomeric pump containers, did not meet the recovery acceptance limit. For all test samples, the mean pH consistently decreased during storage, from about 6.4 to about 5.5. Particle counts remained acceptable throughout the study, and no change in appearance was observed. Penicillin G for injection (2,500 and 50,000 units/mL) diluted in 0.9% sodium chloride injection or 5% dextrose injection and stored at 5°C in PVC containers or elastomeric pump containers was physically and chemically stable for a period of at least 21 days.

Antimicrobial activity of copper against organisms in aqueous solution: A case for copper-based water pipelines in hospitals?

An association exists between water of poor quality and health care-associated infections. Copper shows microbiocidal action on dry surfaces; it is necessary to evaluate its antimicrobial effect against organisms in aqueous solution. The objective was to determine the in vitro antimicrobial activity of copper against common nosocomial pathogens in aqueous solution. Copper and polyvinyl chloride containers were used. Glass was used as control material. Fourteen organisms isolated from hospital-acquired infections, and 3 control strains were tested. Inocula were prepared by direct suspension of colonies in saline solution and water in each container tested. Bacterial counts in colony-forming units (CFU)/mL were determined at the beginning of the experiment; at 30 minutes; and at 1, 2, 24, and 48 hours. Organisms in glass and polyvinyl chloride remained viable until the end of the experiment. Organisms in copper showed a reduction from more than 100,000 CFU/mL to 0 CFU/mL within the first 2 hours of contact (F > 4.29, P < .001). Copper containers show microbiocidal action on organisms in aqueous solution. Copper may contribute to the quality of water for human use, particularly in hospitals.

Physico-chemical and sensory quality of fresh cut papaya (Carica papaya) packaged in micro-perforated polyvinyl chloride containers.

Papaya cubes at maturity stages, 5-45% yellow (more green than yellow) and 55-80% yellow (more yellow than green) were washed with 5% H2O2, drained and packaged in PVC trays having five, seven and ten micro-perforations and stored for 19days. PVC trays with 3mm diameter punch holes were used as the control. Based on physico-chemical properties, optimum maturity for papaya and micro-perforation level of PVC trays were determined. Effectiveness of citric acid in prevention of browning was also tested. Firmness and TSS changed significantly, on day 19. O2, CO2 and C2H4 concentration changed 2.4 to 4.2%, 23.4 to 5.9%, and 0 to 0.13% respectively, from day 3 to 19. pH and titratable acidity did not change significantly throughout the storage. Pretreated papaya cubes, packaged in PVC trays with ten micro-perforations, kept under 4°C had storage lives of 19days.

Moulds and Ochratoxin A Occurrence in Cola Nitida Fresh Nuts after Treatment by Fungicide Epoxiconazole and Stored for Several Months in Various Containers

The conservation of fresh kolanuts produced in Cote d’Ivoire and intended for the export, poses a veritable problem for the farmers. After 2 or 3 months of storage, the stock of kolanuts dramatically diminished occasioning high loss of economic resources. The aim of the present study was to find strategies for the best conservation for long period by investigation in appropriated nature of container, temperature of storage and in a possible fungicide adequate for kolanuts. Three (03) containers namely traditional made from the leaves of Thaumatococcus daniellii (Benn.) Benth., polyvinyl chloride (PVC) container and perforated cardboard have been studied. The temperatures of storage investigated were 26°C and 29°C while epoxiconazole is used as the fungicide. Fungi and Ochratoxin A (OTA) occurrence have been taken as bio-indicators of kolanuts healthy. Fungi were isolated by using Potato Dextrose Agar (PDA) and standard laboratory methods while OTA was extracted with a methanol/3% sodium hydrogen carbonate solution and purified using an immunoaffinity column prior to HPLC analysis with fluorescence detection. As results, the best temperature of storage could be 26°C and the container PVC had been found more efficient in fungi reduction in kolanuts when compared to traditional container made from leaves of Thaumatococcus daniellii (Benn.) Benth. In addition, OTA levels are stayed lows after 10 months of kolanuts storage. Moreover, the fungicide epoxiconazole was able to prevent Aspergillius flavus proliferation and retarded both Penicillium sp. contamination and OTA secretion in kolanuts until 6 months of storage. Taken together, the results suggested that a combination of the using of PVC container and fungicide epoxiconazole and 26°C as temperature of storage could improve significantly the conservation of fresh kolanuts for several months.

Comparison of container system residual volumes and the implications for medication error

ObjectivesPlastic intravenous containers can be categorised as flexible polyvinyl chloride (PVC), flexible non-PVC and semirigid plastic. The characteristics of the container may have an effect on the total volume of...

Modification and Development of a Blow Molding Machine

This study is based on the modification and development of a two-liter plastic container blow molding machine into a five-liter one provided with a translucent view stripe. This study considers some objectives including reducing the total cost, increasing the amount of plastic recovery, and raising the desired plastic materials. Proper designs were prepared and directly applied on spot. Tangible results were obtained. Among others, the modification of some components of the machine, e.g. the extruder, has led to the possible reuse of the milled (recovery) and extra material from the manufacturing processes. That was also conducive to an effective reduction in the cost of production to 50% in some cases. Prior to its modification, this old machine was used to produce polyvinyl chloride (PVC) containers that have become prohibited these days for their damaging effect on man’s life. For now, and after modification, it has become possible to use High Density Polyethylene (HDPE) material, a fact that has improved labor conditions, too.

Migration of phthalate-based plasticizers from PVC and non-PVC containers and medical devices

The presence of five plasticizer phthalates in bags and sets for intravenous administration and hemodialyzers (HD), which are made of polyvinyl chloride (PVC) and of other polymeric materials, was investigated. Di-(2-ethylhexyl) phthalate (DEHP) in PVC is the only authorized phthalate by regulatory agencies. Phthalate determination was carried out by high resolution liquid chromatograph (HPLC) with UV detection. The results showed that the infusion bags that are made of both PVC and ethylene vinyl acetate (EVA) contained only DEHP. In contrast, the tubing of infusion sets and of HD (as well as the cellulose capillaries of HD) contained not only DEHP but also dibutyl phthalate (DBP). Moreover, all five investigated phthalates were found in HD polysulfone capillaries. Migration of DEHP into the stored solutions (amino acids, glucose and saline) in bags occurred at different rates from one polymer to another. While DEHP from PVC bags was found in solutions within the first days of contact, the migration from EVA bags started only after approximately 6 months of solution storage. Since PVC and non-PVC devices (as well as capillaries of HD sets) contain DEHP and other phthalate-based plasticizers, the extent of the risk that they pose to patients remains a matter of concern.

Efficacy of Heat Treatment for Disinfestation of Concrete Grain Silos

Field experiments were conducted in 2007 and 2008 to evaluate heat treatment for disinfestations of empty concrete elevator silos. A Mobile Heat Treatment Unit was used to introduce heat into silos to attain target conditions of 50 degrees C for at least 6 h. Ventilated plastic containers with a capacity of 100 g of wheat, Triticum aestivum L., held Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) and Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). Polyvinyl chloride containers with a capacity of 300 g of wheat held adults of Liposcelis corrodens (Heymons) (Psocoptera: Liposcelididae) and Liposcelis decolor (Pearman), which were contained in 35-mm Petri dishes within the grain. Containers were fastened to a rope suspended from the top of the silo at depths of 0 m (just under the top manhole), 10 m, 20 m, and 30 m (silo floor). When the highest temperature achieved was approximately 50 degrees C for 6 h, parental mortality ofR. dominica and T. castaneum, and both psocid species was 98-100%. Progeny production of R. dominica occurred when there was parental survival, but in general R. dominica seemed less impacted by the heat treatment than T. castaneum. There was 100% mortality of L. corrodens at all depths in the heat treatments but only 92.5% mortality for L. decolor, with most survivors located in the bioassay containers at the top of the silo. Results show wheat kernels may have an insulating effect and heat treatment might be more effective when used in conjunction with sanitation and cleaning procedures.

Coal alternative fuel production from municipal solid wastes employing hydrothermal treatment

An experimental study of the conversion of Japanese municipal solid waste (MSW) to solid fuel by using an innovative hydrothermal treatment has been performed. The treatment system is capable of processing up to 1 ton MSW per batch, applies medium-pressure saturated steam at the pressure of approximately 2 MPa in a stirred reactor for one hour. After undergoing the process, MSWs of various sizes and forms became slump materials that were easily dryable to a powdery product with a 10% moisture content and an average heating value of 20 MJ/kg (dry basis), which is equal to that of low-grade sub-bituminous coal. Because the MSW used in the experiments contained a significant amount of plastics, the reduction of chlorine content, which is known to promote clogging, corrosion, and dioxin formation in the furnace, was imperative. It was observed that water-insoluble organic chlorine generated from poly vinyl chloride containers was approximately 10,000 ppm (dry basis) in the raw MSW and was reduced to approximately 2000 ppm (dry basis) because of the transformation to water-soluble inorganic chlorine during the hydrothermal process. These changes in chlorine content were very evident at elevated temperature and pressure. These results indicate that the hydrothermal treatment is a viable way to treat MSW and obtain an alternative low chlorine content solid fuel.

Stability of doripenem in polyvinyl chloride bags and elastomeric pumps

The stability of doripenem 500 and 1000 mg in polyvinyl chloride (PVC) bags and elastomeric pumps at various storage temperatures was evaluated. Commercially available doripenem vials were reconstituted and mixed with either 0.9% sodium chloride injection or 5% dextrose injection to produce 100-mL solutions with concentrations of 5 and 10 mg/mL. Six replicate solutions in either PVC bags or elastomeric pumps were prepared. Bags were sampled immediately after preparation and stored at 25 degrees C, 4 degrees C, or -20 degrees C. Those stored at 25 degrees C were sampled for an additional 48 hours, and bags stored at 4 degrees C were sampled for 12 days. Bags frozen at -20 degrees C for 14-28 days were allowed to thaw at either 25 degrees C for 4-6 hours or 4 degrees C for 24 hours and sampled for an additional 48 hours. Solutions retaining > or =90% of the initial concentration were considered stable. At 25 degrees C, both concentrations were stable for 24 hours in 0.9% sodium chloride injection and for 16 hours in 5% dextrose injection. At 4 degrees C, 5-mg/mL solutions were stable for 10 days in both 0.9% sodium chloride injection and 5% dextrose injection, while 10-mg/mL solutions were stable for 10 days in 0.9% sodium chloride injection and 7 days in 5% dextrose injection. A white precipitate, which returned to solution by shaking, was noted after thawing the frozen containers. Whether thawed at 4 degrees C or 25 degrees C, both 5- and 10-mg/mL solutions were stable for 16 hours at 25 degrees C. Doripenem 5- and 10-mg/mL solutions were stable for 24 hours at 25 degrees C when diluted in 0.9% sodium chloride injection. When diluted in 5% dextrose injection, the stability of both concentrations of doripenem decreased to 16 hours at 25 degrees C. When stored at 4 degrees C, 5-mg/mL solutions in either 0.9% sodium chloride or 5% dextrose injection were stable for at least 10 days, and all solutions containing doripenem 10 mg/mL were stable for at least 7 days. Both concentrations of doripenem were stable for 16 hours when previously frozen and thawed at 25 degrees C and 4 degrees C. The rate of doripenem degradation was similar between PVC and elastomeric containers.

Effect of Relative Humidity and Product Moisture on Response of Diapausing and Nondiapausing Indianmeal Moth (Lepidoptera: Pyralidae) Larvae to Low Pressure Treatments

Low pressure treatment in flexible polyvinyl chloride containers is a potential alternative to chemical fumigants for California tree nuts. Laboratory studies investigated the effect of relative humidity and product moisture on weight loss and mortality of diapausing and nondiapausing larvae of the Indianmeal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), exposed to 50 mmHg. Diapausing larvae were far more tolerant than nondiapausing larvae to low pressure; exposure times nearly twice those of nondiapausing larvae were required to obtain comparable weight loss or mortality levels in diapausing larvae. Relative humidity was found to have a large effect on both weight loss (assumed to be due to moisture loss) and mortality of both nondiapausing and diapausing larvae. Mortality and weight loss increased as humidity levels decreased. By controlling the relative humidity of the treatment chamber, product moisture also strongly affected weight loss and mortality. The results suggest that for tree nuts, product moisture levels may affect the efficacy of low pressure treatments.