Lee Janaway

Development of a boxing dynamometer and its punch force discrimination efficacy

The development of sport-specific dynamometers is an important step towards ecological validity in analysing athlete performance. Design limitations in previous punch-measuring devices have resulted in values which may not or cannot fully reflect the force and multidirectional components in a punch. In developing this boxing dynamometer, a triaxial force measurement system and a boxing manikin interface were combined. The repeatability and accuracy of the dynamomoter were assessed using simulated straight punches. Discrimination efficacy was assessed by comparison of the maximal punching force of seven elite, eight intermediate and eight novice boxers during simulated boxing, throwing straight punches. For the elite, intermediate and novice groups, respectively, the maximal straight punching forces (mean - s x ¥ ) were 4800 - 227 N, 3722 - 133 N and 2381 - 116 N for the rear hand, and 2847 - 225 N, 2283 - 126 N a d 1604 - 97 N for the lead hand. For all groups, maximal forces were larger for the rear than the lead hand ( P ≪ 0.001). Maximal punching force was greater in the elite than the intermediate group, and greater in the intermediate than the novice group ( P ≪ 0.05). The boxing dynamometer discriminated eff ectively between punching performance at three standards of performance and between the punching force of the rear and lead hands.

Minimising Solvent Usage in High Speed, High Loading, and High Resolution Isocratic Dynamic Extraction

Abstract The development of the planetary‐motion countercurrent chromatography machine into a high speed, high loading and high resolution dynamic extraction centrifuge has allowed the scale‐up of the technique from analytical to pilot (kg/day). At this scale, solvent usage is a major consideration for both economical and environmental (“green”) reasons. The analysis by gas chromatography of the composition of the two phases in solvent systems allows each layer to be made separately as required, minimising solvent wastage. Furthermore, as operation is generally isocratic, analysis of the recovered condensate from evaporated fractions allows the mobile phase to be easily reconstituted ready for re‐use in the centrifuge. Such recycling further minimises solvent usage during preparative and pilot‐scale separations.

Stationary Phase Retention in CCC: Modelling the J‐Type Centrifuge as a Constant Pressure Drop Pump

Abstract To be able to design a J‐type centrifuge for a given need, a method of being able to predict peak elution is required. Predicting peak elution will also allow the user to optimise the process parameters for his or her needs. Such predictions require an accurate knowledge of the volume of the stationary phase retained in the coil for a given set of operating conditions. This paper builds upon an experimental relationship in that the stationary phase retention decreases proportionally to the square root of the mobile phase flow rate. Combining this experimental relationship with the hypothesis that the pressure drop across a coil is independent of mobile phase flow rate, and assuming that the mobile phase flow is laminar, the equation below is derived: Experimental evidence is presented supporting the above equation. The experimental evidence was gained using, a heptane–ethyl acetate–methanol–water (1.4:0.1:0.5:1) v/v phase system, in normal phase mode using three helical stainless steel coils. These stationary phase retention studies allowed the above equation to be tested under conditions of different rotational speeds and tubing internal diameter. The derived stationary phase retention characteristics from each retention study allowed pressure drop and Reynolds number data to be calculated. The pressure drop data shows that the pressure drop across a coil is constant and independent of the mobile phase flow rate.

Review of Progress Toward the Industrial Scale‐Up of CCC

Abstract Considerable advances have been made in the last two years on the industrial scale‐up of countercurrent chromatography. This paper briefly reviews the scale‐up progress being made by three groups, two in France and one in the UK before giving details of advances being made at Brunel Institute for Bioengineering, Brunel University in the UK on the scale‐up of their J‐type centrifuges.

Comparison of preparative reversed phase liquid chromatography and countercurrent chromatography for the kilogram scale purification of crude spinetoram insecticide

Reversed phase HPLC (RP-HPLC) and high performance countercurrent chromatography (HPCCC) were compared for the pilot scale purification of two semi-synthetic spinosyns, spinetoram-J and spinetoram-L, the major components of the commercial insecticide spinetoram. Two, independently performed, 1 kg, purification campaigns were compared. Each method resulted in the isolation of both components at a purity of >97% and yields for spinetoram-J and spinetoram-L of >93% and ≥ 63% of theoretical, respectively. The HPCCC process produced a 2-fold higher throughput and consumed approximately 70% less solvent than preparative scale RP-HPLC, the volume of product containing fractions from HPCCC amounted to 7% of that produced by HPLC and so required much less post-run processing.

Ground reaction force measures when running in soccer boots and soccer training shoes on a natural turf surface

There are differences in ground reaction force when wearing soccer boots compared with training shoes on a natural turf surface. Two natural-turf-covered force platforms, located outdoors in a field, allowed comparison of performance when six-studded soccer boots and soccer training shoes were worn during straight fast running (5.4 m s-1 ± 0.27 m s-1) and slow running (4.4 ms-1 ± 0.22 m s-1). Six male soccer players (mean age: 25 ± 4.18 years; mean mass 79.7 ±9.32 kg) struck the first platform with the right foot and the second platform with the left foot. In fast running, the mean vertical impact peak was significantly greater in soccer boots (2.706 BW) than in training shoes (2.496 BW) when both the right and left foot were considered together and averaged (P = 0.003). Similarly, the mean vertical impact peak loading rate was greater when wearing soccer boots at 26.09 BWs-1 compared to training shoes (21.32 BWs-1;P = 0.002). Notably, the mean vertical impact peak loading rate of the left foot (boots: 28.07 BWs-1; shoes: 22.52 BWs-1) was significantly greater than the right foot (boots: 24.11 BWs-1; shoes: 20.11 BWs-1) in both boots and shoes (P = 0.018). The braking force was greater for the left foot (P = 0.013). In contrast, mean peak vertical propulsion forces were greater for the right foot (P > 0.001) when either soccer boots or training shoes were considered. Similar significant trends were evident in slow running, and, notably, in both soccer boots and training shoes medial forces were greater for the left foot (P = 0.008) and lateral forces greater for the right foot (P = 0.011). This study showed the natural turf ground reaction force measurement system can highlight differences in footwear in an ecological environment. Greater forces and impact loading rates occurred during running activity in soccer boots than in training shoes, with soccer boots showing reduced shock attenuation at impact. Such findings may have implications for impact-related injuries with sustained exposure, especially on harder natural-turf surfaces. There were differences in the forces occurring at the right and left feet with the ground, thus suggesting the use of bipedal monitoring of ground reaction forces.

INDUSTRIAL SCALE-UP OF COUNTERCURRENT CHROMATOGRAPHY

The hydrodynamic, engineering, and chromatographic variables affecting scale-up of countercurrent chromatography (CCC) are examined. The predictable and linear scale-up from the current laboratory scale technology to industrial process scale, capable of kgm/month in the first phase, is demonstrated. Continued research will prepare the way for a new generation of tonne/annum capacity high throughput, high resolution CCC machines for pilot and plant scale separations of a range of bioprocess products.

A new small coil-volume CCC instrument for direct interfacing with MS

Abstract One of the major factors restricting the use of CCC as an analytical tool is the speed at which a separation may be conducted. This paper describes the phased development of a new low volume capacity Milli‐CCC device, which is as rapid as HPLC, achieving high resolutions in minutes as opposed to hours, with the capability of linking with a mass spectrometer (CCC/MS). The Milli‐CCC J‐type apparatus has gears enclosed in a lubricated case to minimize noise. Its volume with one coil mounted in a cantilever style is 4.6 mL with 2.5 m of 0.76 mm bore tubing. It can rotate at a maximum speed of 2100 rpm. Stationary phase retention factor higher than 60% could be obtained with 1500 rpm and 1 mL/min producing separation of compounds with K D distribution coefficient of 1 in less than 5 min. The connection to MS was straightforward.

Scalable Technology for the Extraction of Pharmaceutics (STEP): The transition from academic knowhow to industrial reality

This paper addresses the technological readiness of counter-current chromatography (CCC) instruments to become platform technology for the pharmaceutical industry. It charts the development of the prototype technology since its inception in 1966, through conceptual improvements in the 1980s that led to higher speed separations in hours as opposed to days. It then describes the engineering improvements that have led to the development of high performance counter-current chromatography with the potential for scale-up to process scale for manufacturing products in industry with separation times in minutes rather than hours. A new UK Technology Strategy Board high value manufacturing £1.5 m research programme to take CCC through to technology readiness level 8 (i.e. as platform technology for continuous 24 × 7 operation by industry) is introduced. Four case studies are given as examples of successes from its expanding applications portfolio, which is mainly confidential. Finally, the hurdles for the uptake of new technology by industry are highlighted and the following potential solutions given: rapid method development, automation, continuous processing and instrument reliability and robustness. The future challenge for the CCC community will be to address these development needs urgently if CCC is to become the platform technology it deserves to be.

Resolution in CCC: The Effect of Operating Conditions and Phase System Properties on Scale‐Up

Abstract Being able to accurately predict the eluted volume of a substance with a known distribution ratio will depend on accurately knowing the retention volume of the stationary phase. Sample resolution depends on a number of factors that are not so easy to predict: the properties of the phase systems, the number of mixing and settling cycles per unit time, the rate of mass transfer during mixing, and the quality of mixing between the phase systems. The extent of mixing between the phases will, in turn, depend on the flow rate of the mobile phase and the “g” field acting across the stratified phases within the coiled tubing. A systematic study is made of how sample resolution changes with the key operating variables associated with scale‐up: the mobile phase flow, the bore of the tubing, and the rotational speed. It shows how the commonly accepted characteristic, good resolution at low flow and poor resolution at high flow, slowly changes as tubing bore increases to one of poor resolution at low flow rising to optimum resolution at high flow and a slow decline in resolution at very high flow. Furthermore, it goes on to show that, as phase system physical properties change when moving from hydrophobic phase systems to more polar hydrophilic ones, the optimum resolution remains in a similar speed and flow range. It also shows that the key variable for scale‐up, the throughput of sample in kg/hour, increases significantly as mobile phase flow increases, provided the rotational speeds are high enough. Optimum throughput has not yet been reached, which is extremely promising for realising process scale CCC.