Intensive Inspection Research Articles

SUSCEPTIBILITY OF RED SPRING WHEAT, TRITICUM AESTIVUM L. CV. KATEPWA, DURING HEADING AND ANTHESIS TO DAMAGE BY WHEAT MIDGE, SITODIPLOSIS MOSELLANA (GÉHIN) (DIPTERA: CECIDOMYIIDAE)

AbstractIn a 3-year field study, potted plants of ‘Katepwa’ wheat, Triticum aestivum L., were exposed to ovipositing wheat midge. Sitodiplosis mosellana (Géhin), to determine when spikes are most susceptible to damage. After exposure, plants were maintained under controlled conditions for 4 weeks and examined for wheal midge larvae and damaged kernels, ‘Katepwa’ wheat became susceptible to wheat midge damage shortly after spikes emerged from the boot leaf. Location of larvae and damaged kernels within spikes was influenced by the duration spikelets were exposed to oviposition and pattern of anthesis within spikes. In 1992, frequencies of larvae and damaged kernels were 60–90 times higher in spikes exposed to oviposition during advanced heading (stages 57–59, Zadoks’ code) than in those exposed during flowering (stages 61–69). Kernel damage in spikes exposed to oviposition during stages 57–59, 61–65, and 65–70 was 48.5, 3.2, and 0.2%, respectively, in 1993 and 21.2, 1.0, and 0.6%, respectively, in 1994. Data indicated that susceptibility to midge damage declined 15- to 25-fold between heading and early anthesis and 35- to 240-fold between heading and advanced anthesis. Potential factors contributing to these declines and concomitant reductions in larval frequencies are discussed.Commercial fields of ‘Katepwa’ wheat should be monitored for ovipositing wheat midge throughout heading (stages 51–59) when spikes are most vulnerable to damage. Larval survival and kernel damage were so low after stage 61 that monitoring during anthesis should be unnecessary. Intensive inspection of fields throughout heading would ensure that chemical treatments are applied when they are necessary and most effective.

Process modeling and manufacture: Where we stand

The term "process" is broadly defined as the means by which a manufacturing organization converts raw materials into a finished product. This includes people and equipment operating together in a managed and planned system. In addition to the efficient use oflabor and production equipment, an ideal process turns out a product with a 100% yield and no waste of raw materials. Typical real processes produce products with variations in characteristics, suffer from equipment downtime, and waste raw materials. Real processes also are sensitive to human behavior, machine performance, and the characteristics of raw materials. Often, attempts to increase the throughput of a process lead to an increase in the sensitivity to such variances. The traditional approach to maintain product quality within acceptable limits has been increasingly intensive product inspection to remove unacceptable products from the production line. Of course, such inspection is costly and time-consuming. In today's environment, which places an emphasis on total quality control (TQC), the trend is to couple process design and control together. An ideal, properly controlled process will yield only good products. Complete process control obviates the need for product inspection (or at least limits it to first article verification or occasional spot checks). The need to control manufacturing processes is forcing manufacturing technologists to seek a scientific description of manufacturing processes and the response of raw materials, equipment and semi-finished products to these processes in order to simulate the entire manufacturing process, and thus obtain near-optimal solutions for producing the desired product qualities. This is process modeling. The objective is to achieve efficient manufacturing processes without the need for the costly trial-and-error search for viable manufacturing processes. Analyses of this type rely on the

The qualities of validation

ABSTRACT Demands for enhanced quality and quality control in higher education, such as those contained in the 1987 White Paper, often involve increased stress on validation. This emphasis on a peculiarly British system of peer review of courses suggests that an examination of some of the qualities of validation may be helpful in ensuring that it continues to achieve the ends expected of it. The structure of validation generally requires action at course (or department), faculty and institutional levels. Validation can operate in at least three modes: initial approval of new courses, regular monitoring of performance and intermittent but more intensive inspections of course organisation and achievement. In all three modes the basic structures function in a way that uses specific inputs, processes and outputs. Amongst the inputs are admissions, resources, staffing and curricula. The processes involve such feedback mechanisms as continuous assessment together with staff development. Training in validation skills is but rarely provided. Outputs are reviewed through final examinations, the external examiner system and outside visitations. The question which arises is whether this system is an adequate form of quality control. The conclusion is that, while it has certain methodological weaknesses, validation is a legitimate and defensible tool. But, if it is to succeed in new circumstances, more thought about its qualities and the means of developing them is necessary.

High-Strength Heavy-Wall Casing for Deep, Sour Gas Wells

Summary A completion program for a high-pressure deep, sour gas well (DSGW) requires exceptionally heavy-wall large-diameter casing, particularly where an additional tubing string is required to provide for continuous chemical injection and tubing set on a packer. Production and protection casings of unprecedented weight and thickness were obtained recently for such a well. This paper describes the qualification program for these casings and the specifications and controls used to ensure acceptable sulfide stress cracking performance. The specifications are the result of prototype casing and connection testing in H2S to 25,000-psi (172000-kPa) internal pressure and 1 million-lbf (4450-kN) axial load. New mill specifications including microstructural control and sulfide stress cracking tests are discussed along with the justification for such controls. Connection design including a new non-galling connection used on the protective string is discussed as well as the triaxial stress analysis used for high-pressure casing design. Manufacturing process control, nondestructive testing (NOT), and intensive follow-up inspections for these strings also are discussed. Introduction Exxon Co. U.S.A. has drilled a deep, abnormal-pressure sour gas wildcat in central Mississippi. The completion concept1 for this well includes the use of a 4-in. (I0.2-cm) special alloy tubing and packer2 set at about 12,000 ft (3660 m) and a 2 3/8-in. (6.03-cm) concentric tubing string for continuous chemical injection and production. An 18,000-psi (124000-kPa) shut-in design pressure mandated use of 7 3/8-in. (19.4-cm) 90 grade [90,000-psi (621 000-kPa) minimum yield strength] production casing having a wall thickness of 1.2 in. (3.05 cm). For this pressure level, a triaxial stress design that incorporates hydrostatic pressure as an independent radial stress variable along with hoop (burst) arid axial stresses was used. DSGW specifications were written to ensure that the required sulfide stress cracking resistance would be obtained and that the tubes would be mechanically sound. New metallurgical features of the DSGW-90 specification and laboratory and prototype testing that validated the heavy wall casing and connection design are presented along with discussion of the intensive quality assurance (QA) program that was followed. A torque-turn procedure was developed to aid in running the special clearance connection. The 10 1/4-×9 5/8-in. (27.3-×24.4-cm) protective casing string experienced a maximum indicated hook load of 1.48 million lbf (6580 kN) during the hangersetting operation making this a record-weight string for an oil or gas well. Modified API connections were designed to handle the anticipated 1.5 million-lbf (6670-kN) tensile and 14,000-psi (96 500-kPa) maximum burst pressure requirements. The eight-round threaded portion incorporated a recently developed 3 entrance and exit thread profile for improved makeup and anti-galling characteristics. As with the production casing, DSGW specifications were used to ensure that metallurgical and QA characteristics were consistent with critical service requirements. Production Casing Von Mises or Triaxial Stress Tubular Design For low-pressure (design pressure is small compared with usable metal strength) and shallow-well situations, relatively simple and conservative casing design is possible using the API Barlow4 formula for burst and a load/area formula for tensile stresses. Von Mises or Triaxial Stress Tubular Design For low-pressure (design pressure is small compared with usable metal strength) and shallow-well situations, relatively simple and conservative casing design is possible using the API Barlow4 formula for burst and a load/area formula for tensile stresses.

Moving the stones to Stonehenge

Mr Garfitt is a Consultant Forester. He has been forestry adviser to large landed estates all over England and Wales from 1946 when he left the Royal Indian Navy. Before that he followed a degree in Forestry at Oxford by six years in the Colonial Forest Service (Malaya). Mr Garfitt says that his work involves intensive inspection of woodland and provides opportunities for the discovery of earthworks and artifacts. He is interested primarily in the prehistoric periods because of the opportunities they provide for imaginative reconstruction, as those who read on will discover. Mr Garfitt lives at The Swedish House, Spring Hill, Nailsworth, Stroud, Glos. GL6 0LX.

The larval habitats of Aedes polynesiensis marks in Tahiti and methods of control.

The larval habitats of Aedes polynesiensis marks in Tahiti and methods of control.