Design of a Lean Manufacturing System for the Production of Compliant Wind at Sparton Electronics

Increased demands in production numbers and higher expectations for product quality in today’s manufacturing industries have led to initiatives to improve processes through lean concepts. This study was conducted to demonstrate how Lean Manufacturing tools and techniques can be used to redesign a production system. The study focuses on the production of the compliant wind at Sparton Electronics. The compliant wind is one of the key components of a sonobuoy and its primary function is to isolate electrical components such as hydrophones from movement of the surface buoy. The goal of the redesign process is to increase production by focusing on customer demand. Quantitative tools, such as just-in-time production and takt time are used to design the tangible aspects of production. Qualitative tools, such as creating stability, standard work, and flow in production are used to control the intangible aspects. To accomplish the goal of increasing production, this thesis proposes a machine and process that incorporate fundamental Lean Manufacturing concepts. The output is a redesigned manufacturing process and machine that, in theory, increases production by reducing cycle times and work in progress, establishes stability by creating standard work, and eliminates wastes such as wait time and unproductive movement. The new manufacturing system has the ability to meet the customer demand in regards to units produced, and is also capable of increasing daily production by at least 15%. Additionally, utilizing modern components helps alleviate maintenance issues and increase equipment availability

Direct and indirect effect of cannibalism and intraguild predation in the two sibling Harmonia ladybird beetles

In this study, we focused on the direct (i.e., predation) and indirect (i.e., potential threat from coexisting with a larger individual) effects of cannibalism and intraguild predation (IGP) during larval stages of two sibling ladybird beetles. These effects play an important role in the coexistence of the generalist–common Harmonia axyridis and specialist–rare H. yedoensis (Coleoptera: Coccinellidae). Direct predation effect of cannibalism and IGP was asymmetric in the two sibling ladybird beetles; the fourth instar larvae of H. axyridis were better intraguild predators than cannibals, while the reverse was true in the larvae of H. yedoensis. Neither cannibalism nor IGP significantly affected female body weight in either species. Larval H. axyridis surviving exposure to cannibalism or IGP had a reduced number of ovarioles as adults, whereas adult H. yedoensis ovarioles were not affected. For the indirect effects, longer developmental times in males and females and a lower total number of ovarioles in females were detected in H. axyridis. In H. yedoensis, shorter developmental time of males, lighter adult weight and fewer total ovarioles in females were observed. Olfactometer choice experiments clarified that the fourth instar larvae of H. axyridis avoided the first instar conspecific larvae, while those of H. yedoensis were attracted to the odors from H. axyridis and conspecifics. Thus, H. axyridis has an avoidance mechanism only for cannibalism but not for IGP, whereas H. yedoensis does not have any avoidance mechanism. These different behaviors in the direct and indirect effects of cannibalism and IGP observed in the laboratory may play important roles in the coexistence of generalist–common H. axyridis and specialist–rare H. yedoensis in natural conditions, compensating for the large handicap of H. yedoensis at reproductive interference from H. axyridis

Toxicity of Three Insecticides to Lysiphlebus fabarum, a Parasitoid of the Black Bean Aphid, Aphis fabae

The toxicity of three insecticides to Lysiphlebus fabarum (Marshall) (Hymenoptera: Braconidae: Aphidiinae), a parasitoid of Aphis fabae Scopoli (Hemiptera: Aphididae), was investigated using IOBC/wprs protocols. Abamectin 1.8 EC, imidacloprid 350 SC, and pymetrozine 25 WP were tested under laboratory conditions at recommended field rates. Immature stages of the parasitoid were exposed to materials by briefly dipping mummified aphids into insecticide solutions/suspensions or water (controls). Abamectin, imidacloprid, and pymetrozine caused 44.8, 58.5, and 14.5% mortality of mummies, respectively. Insecticides were also applied to broad bean foliage until run-off using a hand sprayer and the contact toxicity of residues was investigated after 1, 5, 16 and 30 day periods of outdoor weathering by caging adult wasps on treated plants for 24 h. One day-old residues of abamectin, imidacloprid, and pymetrozine produced 52.5, 90.0 and 57.0% mortality, respectively, and 5 day-old residues produced 28.1, 77.0 and 18.6% mortality. Sixteen day-old residues produced 8.8, 22.4 and 13.6% mortality, whereas 30 day-old residues produced 0.0, 3.2 and 1.1% mortality, respectively. On the basis of these results, abamectin and pymetrozine were classified as short-lived compounds (Class A) and imidacloprid as a slightly persistent compound (Class B)

Ant Mimicry by an Aphid Parasitoid, Lysiphlebus fabarum

In Iran, Lysiphlebus fabarum (Marshall) (Hymenoptera: Braconidae: Aphidiinae) is a uniparental parasitoid of the black bean aphid, Aphis fabae Scopoli (Hemiptera: Aphididae), that possesses various highly evolved adaptations for foraging within ant-tended aphid colonies. Direct observations and video recordings were used to analyze the behavior of individual females foraging for A. fabae on bean leaf disks in open arenas in the laboratory. Females exploited aphids as hosts and as a source of food, allocating within-patch time as follows: resting - 10.4%, grooming - 8.2%, searching - 11.5%, antennation (host recognition) - 7.5%, antennation (honeydew solicitation mimicking ants) - 31.9%, abdominal bending (attack preparation) 19.7%, probing with the ovipositor (attack) - 10.8%. The mean handling time for each aphid encountered was 2.0 ± 0.5 min. Females encountered an average of 47.4 ± 6.4 aphids per hour, but laid only 1.2 eggs per hour. The ovipositor insertion time for parasitism ranged from 2 sec to longer than a minute, but most insertions did not result in an egg being laid. A. fabae defensive behaviors included kicking, raising and swiveling the body, and attempts to smear the attacker with cornicle secretions, sometimes with lethal results. Food deprivation for 4–6 h prior to testing increased the frequency of ant mimcry by L. fabarum. Females also used ant-like antennation to reduce A. fabae defensive behavior, e.g. the frequency of kicking. L. fabarum attacks primed A. fabae to be more responsive to subsequent honeydew solicitation, such that experienced females improved their feeding success by alternating between the roles of parasitoid and ant mimic. These results reveal the possibility for mutualisms to evolve between L. fabarum and the ant species that tend A. fabae, since L. fabarum receive ant protection for their progeny and may benefit the ants by improving A. fabae responsiveness to honeydew solicitation

Complex Left Atrial Appendage Morphology Is an Independent Risk Factor for Cryptogenic Ischemic Stroke

Importance: Ischemic strokes pose a significant health burden. However, the etiology of between 20 and 40% of these events remains unknown. Left atrial appendage morphology may influence the occurrence of thromboembolic events.Design: A retrospective cross-sectional study was conducted to investigate the role of LAA morphology in patients with atrial fibrillation (AF) and cardioembolic-associated stroke and patients with cryptogenic stroke without atrial fibrillation. LAA morphology is classified into two groups: (1) simple (chicken-wing) vs. (2) complex (non-chicken wing) based on transesophageal echocardiography (TEE) findings. In addition to the LAA morphology, left atrial parameters, including orifice diameter, depth, emptying velocity, and filling velocity, were collected for both groups. Mathematical, computational models were constructed to investigate flow velocities in chicken-wing and non-chicken wing morphological patterns to assess LAA function further.Findings: TEE values for volume, size, emptying, and filling velocities were similar between simple and complex LAA morphology groups. Patients with cryptogenic stroke without coexisting AF were noted to have significantly higher rates of complex LAA morphology. Chicken-wing LAA morphology was associated with four-fold higher flow rate (kg/s) in computational simulations.Conclusions: Complex LAA morphology may be an independent contributing factor for cryptogenic strokes. Further studies are warranted to investigate the mechanism involved in LAA morphology and thromboembolic events

Comparative Effect of Wasp Density in Unisexual and Bisexual Strains of Lysiphlebus fabarum, on Superparasitism in the Black Bean Aphid, Aphis fabae

Introduction: Lysiphlebus fabarum Marshall (Hymenoptera: Braconidae: Aphidiinae) is a common aphidiine parasitoid in central Europe, where it attacks more than 70 species of aphids. Although both unisexual (thelytokous) and bisexual (arrhenotokous) strains of L. fabarum have been reported in Iran, the former appear to be more widely distributed. Aphid control in Iran relies heavily on pesticides in both field and greenhouse settings, whereas any availability of new biological control agents such as L. fabarum would likely aid in reducing pesticide use. One of the most important aspects of implementing a parasitoid as a biological control agent is to determine the best density of parasitoid in the host access, in mass rearing. Parasitoid wasps display a wide array of strategies to dispose of host resources. Superparasitism is parasitism of a host by parasitoids of the same species. In solitary parasitoids, superparasitism almost occurs when hosts are limited or parasitoid density in a patch is high. Acceptance or rejection of a host usually depends on a female parasitoid’s ability to distinguish parasitized and unparasitized hosts. Previously, superparasitism was thought to be a maladaptive strategy, wasteful of both eggs and time, while it is now recognized as adaptive in a number of situations, e.g. under conditions of low host availability, as a mechanism for overwhelming the immune response of hosts. Materials and Methods: In the present study, stock colonies of the unisexual and bisexual strains of the parasitoid were established from materials collected from Zanjan province and Khuzestan province fields, respectively. Both populations of the parasitoid were collected from parasitized black bean aphids feeding on the broad bean, Vicia fabae L. A stock colony of black bean aphids was established with material collected from bean fields in Khuzestan province. The synchronous cohorts of both strains of L. fabarum were produced at 21±1 ºC, 50–60% r.h., and L14:D10 photoperiod, and then introduced (one day old) separately into 40 2nd instar nymphs in different densities (1, 5, 10, 15 and 30). The females were removed after 24 hours and parasitized aphids were dissected three days after parasitism to determine the number of wasp larvae in each host. As well as, in another experiment the super parasitized aphids were dissected in three consecutive days (3.5, 4.5 and 5.5) to determine the process of competitors’ elimination. Results and Discussion: According to results, in both strains, wasp densities affected on parasitism rates. In the bisexual strain, females parasitized more aphids in 20 and 30 densities treatments than one density treatment, while this rate did not differ significantly between 1, 5, 10 and 15 densities treatments. In the unisexual strain, single females significantly parasitized fewer hosts than other treatments, but there was no difference between other densities treatments. When in each density, percentage parasitism was compared between two strains, in the density of one female, bisexual females parasitized significantly higher than unisexual ones, in contrast to the density of 30, which significantly more larvae were counted in hosts of the unisexual strain than bisexual ones. In other densities, there was no significant difference between two strains. In the second experiment, which the rate of superparasitism was compared in different densities, in bisexual strain, the rate of superparasitism significantly was lower in the density of one female than other treatments. The number of larvae did not differ significantly between other densities treatments. In the unisexual strain, the rate of superparasitism significantly was lower in the density of one female than other treatments. The most rate of superparasitism was observed in 20 and 30 density treatments. When in each density, the rate of superparasitism was compared between both strains, in 1, 5 and 10 densities, bisexual females superparasitism significantly higher than unisexual ones, in contrast to the density of 30 females, which significantly more larvae were counted in hosts of the unisexual strain than the hosts of bisexual ones. In association with the process of competitors’ elimination, bisexual strain larvae eliminated rival larvae over time (in three consecutive days, including days 3.5, 4.5 and 5.5), as the numbers of larvae were decreased in densities of 5, 20 and 30 females. While in unisexual strain, elimination of rival larvae was not observed over time. Conclusion: Wasp densities affected by parasitism rates and the rate of superparasitism in both strains. In mass rearing, the best density of wasps can be defined as the density that most available hosts are parasitized with a minimum of superparasitism, because superparasitism can depredate the time and eggs of female foragers. The results showed that densities of one and 5 females (for 40 individuals of 2nd instar nymphs) can be suggested as the proper densities of females in bisexual and unisexual strains, respectively. The results of this study can be useful in mass rearing and release of both L. fabarum strains

The Effects of Constant and Fluctuating Thermal Regimes for Reducing Chill Injuries During Cold Storage of Late-Instar Larva of Lysiphlebus fabarum (Hym., Braconidae)

Introduction: Mass production of natural enemies has been considered a necessity for biological control programs. Most beneficial insects have a relatively short shelf-life, so suppliers do not have a sufficient number of biocontrol agents. The development of storage techniques for biocontrol agents provides flexibility and efficiency in mass production. Cold storage by prolonging insect development times provides a steady and sufficient supply of insects and synchronizes a desired developmental stage of biocontrol agents with times of pest outbreaks; so it reduces the cost of biocontrol programs by enlarging the production period over several months. Cold storage is usually associated with major fitness costs. Even if the insects remain alive after cold storage, a reduction of fitness may be observed, so the production of high quality natural enemies must be ensured. Developing effective methods is necessary in mass-producing. It has been reported that using fluctuating thermal regimes (FTR) (i.e. cold exposure interrupted by periodic short pulses of high temperature) versus constant thermal regimes (CTR) can progress the quality of biological control agents and significantly reduce rates of mortality. In this study, the impact of fluctuating thermal regimes versus constant low temperatures on the emergence rate, sex ratio, post-storage development time, adult size, egg load and egg size of the parasitoid wasp, Lysiphlebus fabarum (Marshall) was studied. The test was examined in three cold storage periods (1, 2, or 3 weeks). Lysiphlebus fabarum is an aphidiine parasitoid which attacks more than 70 species of aphids. Although both sexual (arrhenotokous) and asexual (thelytokous) populations of L. fabarum have been reported in Iran, the former population has been studied in this research. Materials and Methods: A stock colony of black bean aphid, Aphis fabae Scopoli (Hemi., Aphididae) was established from material collected in bean fields in Khuzestan province, Iran, in spring 2012. A sexual population of the parasitoid wasp, L. fabarum was collected from black bean aphids feeding on broad bean, Vicia fabae L. The synchronous cohort of L. fabarum was produced on the 2nd instar of aphid (at 21±1 ºC, 50–60% r.h., and L14:D10 photoperiod), then 30 two-day-old mated females were introduced into aphid colony consisting of 200 2nd instar individuals. The females were removed after 10 hours and parasitized aphids were reared for 54 hours (±6) to complete development to the late-instar larvae. These parasitized aphids, which were harboring late-instar larvae of wasp, were subjected to 6 ºC (as constant temperature regime) or were stored at 6 ºC with 2 hours daily exposure to 21±1 ºC (as the fluctuating temperature regime). The experiment was replicated with three cold storage periods (1, 2, or 3 weeks) with a control (direct development at 21±1 ºC). After completion of each storage temperature treatment, insects were transferred back to 21 °C until the emergence of adult wasps. Accordingly, the survival rate and the sex ratio (% females) were determined. The emerged wasps were then exposed to alcohol vapor for 2 minutes. The hind tibia of both gender was measured. Subsequently, the ovaries of each female were dissected to determine the egg load and egg size. Results and Discussion: According to results in CTR, survival of larvae was significantly reduced after one week of storage, and there was a gradual decrease in the second week, but there was no difference between survival of wasps that were stored after one and two weeks of storage. In FTR, emergence rate was decreased after one and two weeks of storage in comparison to the control, and the least survival was observed in the third week. When the survival was compared between different thermal regimes, FTR increased the survival in the first and second weeks, whereas after three weeks of storage there was no significant difference between two thermal regimes. In CTR, the least sex ratio of wasps was observed in those stored for two weeks, although there was no significant variation in sex ratios for control, one week and three week of storage. In FTR, cold storage did not affect on sex ratios of treatments. When the sex ratio was compared between different thermal regimes, for two and three weeks of storage, it was significantly higher in FTR and CTR, respectively. In females and males, larval storage increased development time relative to controls, in CTR. While in FTR, developmental time was decreased after two and three weeks of storage, in FTR. When developmental time was compared between two thermal regimes, post-storage development was slower in CTR after two and three weeks of storage in comparison to FTR, in both genders. In both thermal regimes, cold storage of wasps as larvae resulted in smaller male and female wasps relative to controls over all the storage periods. Egg load and egg size at emergence were progressively diminished as a function of the storage period, regardless of the thermal regimes. Egg load of wasps stored in CTR compared with FTR, was significantly higher for three weeks of storage. For all storage periods, egg size was significantly higher in FTR than CTR. Conclusion: Collectively, our results confirmed the beneficial effect of FTR relative to CTR, when larvae of L. fabarum were stored for two weeks at 6 °C. Although FTR reduced the development time, which could be a problem during delivery for mass release of natural enemies in the field, but the emergence rate, the sex ratio, the body size and the egg size were significantly higher in FTR than those in CTR. For three weeks of storage, FTR was more stressful than the CTR, as the wasps that were stored in CTR had significantly more post-storage development, sex ratio, body size and egg load than the fluctuating ones

Suggested methods for the preparation and testing of various properties of resins and grouts

In the absence of bolting standards for strata reinforcement in the Australian mines, though individual mines or companies have their in house practices, there remains a visible vacuum in assessing credibly the various properties of chemical resins and cementitious grouts. Currently, all methods used in evaluating the mechanical properties of both chemical resins and other bolting reinforcement grouts are dependent on the American, British and South African standards and accordingly there is no uniform and unified methodology of testing. A simplified approach has been discussed to enable mine operators and other interested parties to determine various pertinent properties of chemical resins and grouts in the bolting system only and this paper describes the various methods used to test a set of resin properties. A special Resin Mixing Container (RMC) was developed to permit multiple resin samples to be cast with consistent resin / grout quality. Various conclusions were drawn from the study enabling a better understanding between suppliers and end users

Effects of Three Artificial Diets on Life History Parameters of the Ladybird Beetle Stethorus gilvifrons, a Predator of Tetranychid Mites

Background: The ladybird beetle Stethorus gilvifrons (Mulsant) is an important natural enemy of tetranychid mites and functions as a biological control of these plant pests. The development, survival and reproduction of S. gilvifrons were studied when fed on three artificial diets. The components of the artificial diet that S. gilvifrons could be reared successfully on for one generation with no use of tetranychid mites were examined. Methods: Artificial diets consisted of sucrose, honey, royal jelly, agar, yeast, date palm pollen supplemented in different diets with hen’s egg yolk (AD1, as basic diet), Ephestia kuehniella Zeller eggs (AD2), or E. kuehniella eggs and 2,4-dihydroxybenzoic acid (AD3). Results: Adults and larvae of Stethorusgilvifrons fed on AD1 had a shorter immature development and preoviposition periods than those fed on AD2 and AD3. The total number of deposited eggs was significantly higher for the females fed on AD3 than on the other diets. The intrinsic rate of increase (r) of S. gilvifrons was highest on AD3, followed by AD2, and AD1. Conclusion: Stethorus gilvifrons performed best on AD3, indicating the potential of this artificial diet for the mass rearing of this important predatory ladybird beetle